OMEGA
1. Twenty-fourth and last letter of the Greek alphabet, omega. 2. Symbol for Ohm.



Copyright© 1995 Williams & Wilkins. All rights reserved.

O O
1. Symbol for oxygen; orotidine. 2. Abbreviation for opening (in formulas for electrical reactions). 3. Symbol for a blood group in the ABO system. See ABO blood group, Blood Groups appendix. 4. An abbreviation derived from ohne Hauch (without a film), used as a designation for: 1) antigens that occur in the bacterial cell, in contrast to those in the flagella; 2) specific antibodies for such somatic antigens; 3) the agglutinative reaction between somatic antigen and its antibody.



Copyright© 1995 Williams & Wilkins. All rights reserved.

15O 15O
Symbol for oxygen-15.



Copyright© 1995 Williams & Wilkins. All rights reserved.

16O 16O
Symbol for oxygen-16.



Copyright© 1995 Williams & Wilkins. All rights reserved.

17O 17O
Symbol for oxygen-17.



Copyright© 1995 Williams & Wilkins. All rights reserved.

18O 18O
Symbol for oxygen-18.



Copyright© 1995 Williams & Wilkins. All rights reserved.

o- o-
In chemistry, the abbreviation for ortho- (2) .



Copyright© 1995 Williams & Wilkins. All rights reserved.

oak apple oak apple
nutgall



Copyright© 1995 Williams & Wilkins. All rights reserved.

oari- oari- , oario-
Obsolete term for an ovary. See oo-, oophor-, ovario-. [G. oarion, a small egg, dim. of oon, egg]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oath oath (oth)
A solemn affirmation or attestation. See Hippocratic Oath, Veterinarian's Oath.



Copyright© 1995 Williams & Wilkins. All rights reserved.

OB OB
Abbreviation for obstetrics.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obdormition obdormition (ob-dor-mish´un)
Numbness of an extremity, due to pressure on the sensory nerve. [L. ob-dormio, pp. -itus, to sleep]



Copyright© 1995 Williams & Wilkins. All rights reserved.

O'Beirne O'Beirne
James, Irish surgeon, 1786-1862. See O'B.'s sphincter.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obeliac obeliac (o-be´le-ak)
Relating to the obelion.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obeliad obeliad (o-be´le-ad)
Toward the obelion.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obelion obelion (o-be´le-on)
A craniometric point on the sagittal suture between the parietal foramina near the lambdoid suture. [G. obelos, a spit]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Obermayer Obermayer
Friedrich, Austrian physician, 1861-1925. See O.'s test.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Obermeier Obermeier
Otto H.F., German physician, 1843-1873. See O.'s spirillum.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Obersteiner Obersteiner
H., Austrian neurologist, 1847-1922. See O.-Redlich line, zone.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obese obese (o-bes´)
Excessively fat.corpulent; [L. obesus, fat, partic. adj., fr. ob-edo, pp. -esus, to eat away, devour]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obesity obesity (o-be´si-te)
An abnormal increase of fat in the subcutaneous connective tissues.adiposity (1), corpulence, corpulency;
hypothalamic o. o. caused by disease of the hypothalamus.
hypothalamic o. with hypogonadism dystrophia adiposogenitalis
morbid o. o. sufficient to prevent normal activity or physiologic function, or to cause the onset of a pathologic condition.
simple o. o. resulting when caloric intake exceeds energy expenditure.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obex obex (o´beks) [NA]
The point on the midline of the dorsal surface of the medulla oblongata that marks the caudal angle of the rhomboid fossa or fourth ventricle. It corresponds to a small, transverse medullary fold overhanging the calamus scriptorius. [L. barrier]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obfuscation obfuscation (ob-fus-ka´shun)
1. A rendering dark or obscure. 2. A deliberate attempt to confuse or to prevent understanding. [L. ob-fusco, pp. -atus, to darken, fr. fuscus, dark, tawny]



Copyright© 1995 Williams & Wilkins. All rights reserved.

OB/GYN OB/GYN
Abbreviation for obstetrics and gynecology.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obidoxime chloride obidoxime chloride (ob´e-dok-sem)
A cholinesterase reactivator much like 2-PAM.



Copyright© 1995 Williams & Wilkins. All rights reserved.

object object (ob´jekt)
1. Anything to which thought or action is directed. 2. In psychoanalysis, that through which an instinct can achieve its aim. 3. In psychoanalysis, often used synonymously with person.
good o. in psychoanalysis, the good or supporting aspects of an important person in the patient's life, especially of a parent or parent-surrogate.
sex o. a person toward whom another is sexually attracted; a term usually used by a female to indicate that a male narrowly views her as a vehicle for sex while completely disregarding the rest of her persona.
test o. 1. an o. having very fine surface markings, mounted on a slide, used to determine the defining power of the objective lens of a microscope; 2. the target in measurement of the visual field.



Copyright© 1995 Williams & Wilkins. All rights reserved.

object choice object choice
In psychoanalysis, the object (usually a person) upon which psychic energy is centered.



Copyright© 1995 Williams & Wilkins. All rights reserved.

objective objective (ob-jek´tiv)
1. The lens or lenses in the lower end of the body tube of a microscope, by means of which the rays coming from the object examined are brought to a focus.object glass; 2. Viewing events or phenomena as they exist in the external world, impersonally, or in an unprejudiced way; open to observation by oneself and by others. Cf. subjective. [L. ob- jicio, pp. -jectus, to throw before]
achromatic o. an o. that is corrected for two colors chromatically, and one color spherically.
apochromatic o. an o. in which chromatic aberration is corrected for three colors and spherical aberration is corrected for two.
immersion o. a high power o. used with a drop of oil between the lens and the specimen on the slide, allowing a greater numerical aperture; similar lenses are available for use with water as the immersing liquid.



Copyright© 1995 Williams & Wilkins. All rights reserved.

objective assessment data objective assessment data
Those facts presented by the client that show his/her perception, understanding and interpretation of what is happening.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obligate obligate (ob´li-gat)
Without an alternative system or pathway. [L. ob-ligo, pp. -atus, to bind to]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oblique oblique (ob-lek´)
Slanting; deviating from the perpendicular, horizontal, sagittal, or coronal plane of the body. In radiography, a projection that is neither frontal nor lateral. [L. obliquus]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obliquity obliquity (ob-lik´wi-te)
asynclitism
Litzmann o. inclination of the fetal head so that the biparietal diameter is oblique in relation to the plane of the pelvic brim, the posterior parietal bone presenting to the parturient canal.posterior asynclitism;
Nägele o. inclination of the fetal head in cases of flat pelvis, so that the biparietal diameter is oblique in relation to the plane of the pelvic brim, the anterior parietal bone presenting to the parturient canal.anterior asynclitism;



Copyright© 1995 Williams & Wilkins. All rights reserved.

obliquus obliquus (ob-lI´kwus)
Denoting a structure having an oblique course or direction; a name given, with further qualification, to several muscles. See muscle. [L. slanting, oblique]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obliteration obliteration (ob-lit-er-a´shun)
Blotting out, especially by filling of a natural space or lumen by fibrosis or inflammation. In radiology, disappearance of the contour of an organ when the adjacent tissue has the same x-ray absorption. [L. oblittero, to blot out]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oblongata oblongata (ob-long-gah´ta)
medulla oblongata [L. fem. of oblongatus, from oblongus, rather long]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obnubilation obnubilation (ab-nu´bil-a´shun)
A clouded mental state. [L. ob-nubilo, to becloud, obscure, fr. nubes, cloud]



Copyright© 1995 Williams & Wilkins. All rights reserved.

OBS OBS
organic brain syndrome



Copyright© 1995 Williams & Wilkins. All rights reserved.

observer observer (ob-zer´ver)
One who perceives, notices, or watches; in behavioral research with humans, the investigator or his/her surrogate. [L. observo, to watch]
nonparticipant o. an investigator who studies a group of subjects engaged in certain activities but does not directly participate in these activities, presumably being able to study them more objectively.
participant o. an investigator who while studying the activities of a group of subjects also participates in their activities, presumably being able to gain more detailed, relevant information but with less objectivity.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obsession obsession (ob-sesh´un)
A recurrent and persistent idea, thought, or impulse to carry out an act that is ego-dystonic, that is experienced as senseless or repugnant, and that the individual cannot voluntarily suppress. [L. obsideo, pp. -sessus, to besiege, fr. sedeo, to sit]
impulsive o. an o. accompanied by action, sometimes becoming a mania.
inhibitory o. an o. involving an impediment to action, usually representing a phobia.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obsessive-compulsive obsessive-compulsive
Having a tendency to perform certain repetitive acts or ritualistic behavior to relieve anxiety, as in obsessive-compulsive neurosis (e.g., a compulsive, ritualistic need to wash one's hands many dozens of times per day).



Copyright© 1995 Williams & Wilkins. All rights reserved.

obsolescence obsolescence (ob-so-les´ens)
Falling into disuse; denoting the abolition of a function. [L. obsolesco, to grow out of use]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obstetric obstetric , obstetrical (ob-stet´rik, -ri-kal)
Relating to obstetrics.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obstetrician obstetrician (ob-ste-trish´un)
A physician specializing in the medical care of women during pregnancy and childbirth. [see obstetrics]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obstetrics (OB) obstetrics (OB) (ob-stet´riks)
The specialty of medicine concerned with the care of women during pregnancy, parturition, and the puerperium.tocology; [L. obstetrix, a midwife, fr. ob-sto, to stand before, denoting the position formerly taken by the midwife]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obstinate obstinate (ob´sti-nat)
1. Firmly adhering to one's own purpose, opinion, etc. even when wrong; not yielding to argument, persuasion, or entreaty.intractable (2), refractory (2); 2. refractory (1) [L. obstinatus, determined]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obstipation obstipation (ob-sti-pa´shun)
Intestinal obstruction; severe constipation. [L. ob, against, + stipo, pp. -atus, to crowd]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obstruction obstruction (ob-struk´shun)
Blockage or clogging, e.g., by occlusion or stenosis. [L. obstructio]
closed-loop o. o. of a segment of intestine by rotation on a fixed point (volvulus); frequently impairs venous circulation of the affected bowel segment, resulting in strangulation and gangrene; the segment of intestine contained in a hernia can also become a closed-loop o. when sufficient compression occurs at the neck of the sac.
ureteropelvic junction o. an impediment to drainage of urine from kidney usually to partial or intermittent blockage of renal collecting system of the junction of renal pelvis and ureter.
ureteropelvic o. a blocking or stenosis, usually congenital, at the junction of the renal pelvis and ureter, usually resulting in stasis, pelvocaliectasis, hydronephrosis, or calyceal clubbing.
ureterovesical o. o. of the lower ureter at its entrance into the bladder.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obstructive pulmonary overinflation obstructive pulmonary overinflation
Emphysema caused by obstruction of airways that has greater effect on expiration than inspiration; occurs reversibly with bronchospasm of asthma; localized process can be due to aspiration of a foreign body.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obstruent obstruent (ob´stru-ent)
1. Rarely used term for obstructing or clogging. 2. Rarely used term for an agent that obstructs or prevents a normal discharge, especially a discharge from the bowels. [L. ob-struo, to build against, obstruct]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obtund obtund (ob-tund´)
To dull or blunt, especially to blunt sensation or deaden pain. [L. ob-tundo, pp. -tusus, to beat against, blunt]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obturation obturation (ob-tu-ra´shun)
Obstruction or occlusion. [see obturator]
intermittent self-o. passage of a blunt object in a lumen or meatus to occlude it or to dilate it.



Copyright© 1995 Williams & Wilkins. All rights reserved.

obturator obturator (ob´tu-ra-tor)
1. Any structure that occludes an opening. 2. Denoting the obturator foramen, the obturator membrane, or any of several parts in relation to this foramen. 3. A prosthesis used to close an opening of the hard palate, usually a cleft palate. 4. The stylus or removable plug used during the insertion of many tubular instruments. [L. obturo, pp. -atus, to occlude or stop up]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obtuse obtuse (ob-tus´)
1. Dull in intellect; of slow understanding. 2. Blunt; not acute. [see obtund]



Copyright© 1995 Williams & Wilkins. All rights reserved.

obtusion obtusion (ob-tu´zhun)
1. Dullness of sensibility. 2. A dulling or deadening of sensibility.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Occam's razor Occam's razor
the principle of scientific parsimony. William of Occam (14th Century) stated it thus: "The assumptions introduced to explain a thing must not be multiplied beyond necessity."



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipital occipital (ok-sip´i-tal)
Relating to the occiput. referring to the occipital bone or to the back of the head.occipitalis [NA];



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitalis occipitalis (ok´sip-i-ta´lis) [NA]
occipital [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitalization occipitalization (ok´sip´i-tal-i-za´shun)
Bony ankylosis between the atlas and occipital bone.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipito- occipito-
The occiput, occipital structures. [L. occiput]



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitoatloid occipitoatloid (ok-sip´i-to-at´loyd)
Relating to the occipital bone and the atlas; denoting the articulation between the two bones.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitoaxial occipitoaxial , occipitoaxoid (ok-sip´i-to-ak´se-al, -ak´soyd)
Relating to the occipital bone and the axis, or epistropheus.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitobregmatic occipitobregmatic (ok-sip´i-to-breg-mat´ik)
Relating to the occiput and the bregma; denoting a measurement in craniometry.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitofacial occipitofacial (ok-sip´i-to-fa´shal)
Relating to the occiput and the face.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitofrontal occipitofrontal (ok-sip´i-to-frun´tal)
1. Relating to the occiput and the forehead. 2. Relating to the occipital and frontal lobe of the cerebral cortex and association pathways that interconnect these regions.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitofrontalis occipitofrontalis (ok-sip´i-to-frun-ta´lis)
See occipitofrontalis muscle. [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitomastoid occipitomastoid (ok-sip´i-to-mas´toyd)
Relating to the occipital bone and the mastoid process.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitomental occipitomental (ok-sip´i-to-men´tal)
Relating to the occiput and the chin.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitoparietal occipitoparietal (ok-sip´i-to-pa-rI´e-tal)
Relating to the occipital and the parietal bones.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitotemporal occipitotemporal (ok-sip´i-to-tem´po-ral)
Relating to the occiput and the temple, or the occipital and the temporal bones.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occipitothalamic occipitothalamic (ok-sip´i-to-tha-lam´ik)
Relating to the nerve fibers leading from the occipital lobe of the cerebral cortex to the thalamus.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occiput occiput, gen. occipitis (ok´si-put, ok-sip´i-tis) [NA]
The back of the head. [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

occlude occlude (o-klud)
1. To close or bring together. 2. To enclose, as in an occluded virus. [see occlusion]



Copyright© 1995 Williams & Wilkins. All rights reserved.

occluder occluder (o-klud´er)
In dentistry, a name given to some articulators.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occlusal occlusal (o-klu´zal)
1. Pertaining to occlusion or closure. 2. In dentistry, pertaining to the contacting surfaces of opposing occlusal units (teeth or occlusion rims), or the masticating surfaces of the posterior teeth.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occlusion occlusion (o-klu´zhun)
1. The act of closing or the state of being closed. 2. In chemistry, the absorption of a gas by a metal or the inclusion of one substance within another (as in a gelatinous precipitate). 3. Any contact between the incising or masticating surfaces of the upper and lower teeth. 4. The relationship between the occlusal surfaces of the maxillary and mandibular teeth when they are in contact. [L. oc- cludo, pp. -clusus, to shut up, fr. ob., against, + claudo, to close]
abnormal o. an arrangement of the teeth which is not considered to be within the normal range of variation.
afunctional o. a malocclusion which does not permit normal function of the dentition.
anterior o. 1. the o. of anterior teeth; 2. mesial o. (1)
balanced o. the simultaneous contacting of the upper and lower teeth on the right and left and in the anterior and posterior occlusal areas in centric and eccentric positions within the functional range; used primarily in reference to the mouth, but also arranged and observed on articulators, developed to prevent a tipping or rotating of the denture bases in relation to the supporting structures.balanced articulation, balanced bite;
bimaxillary protrusive o. an o. in which both the maxilla and mandible protrude, causing the long axes of the maxillary anterior teeth to be at an extremely acute angle to the mandibular teeth; may be secondary to a skeletal or dental deformity, or both; seen commonly in blacks.
buccal o. 1. malposition of a tooth toward the cheek; 2. the o. as seen from the buccal side of the teeth.
centric o. 1. the relation of opposing occlusal surfaces which provides the maximum planned contact and/or intercuspation; 2. the o. of the teeth when the mandible is in centric relation to the maxillae.centric contact;
coronary o. blockage of a coronary vessel, usually by thrombosis or atheroma, often leading to myocardial infarction.
distal o. 1. a tooth occluding in a position distal to normal;disto-occlusion, postnormal o., retrusive o. (2); 2. distoclusion
eccentric o. any o. other than centric.
edge-to-edge o. an o. in which the anterior teeth of both jaws meet along their incisal edges when the teeth are in centric o.edge-to-edge bite, end-to-end bite, end-to-end o;
end-to-end o. edge-to-edge o
functional o. 1. any tooth contacts made within the functional range of the opposing teeth surfaces; 2. o. which occurs during function.
gliding o. dental articulation
hyperfunctional o. occlusal stress of tooth or teeth exceeding normal physiologic demands.
labial o. 1. malposition of a tooth in a labial direction; 2. the o. as seen from the labial side of the arches.
lateral o. malposition of a tooth or an entire dental arch in a direction away from the midline.
lingual o. 1. linguoclusion 2. interdigitation of the teeth as seen from the internal or lingual aspect.
mechanically balanced o. a balanced o. without reference to physiologic considerations, as on an articulator.
mesenteric artery o. obstruction of arterial flow in the mesenteric circulation by an embolus or thrombus; usually refers to o. of the superior mesenteric artery, although atherosclerotic narrowing may involve all three major splanchnic branches (celiac, superior, and inferior mesenteric).
mesial o. 1. o. in which the mandibular teeth articulate with the maxillary teeth in a position anterior to normal;anterior o. (2), mesio-occlusion; 2. mesioclusion
neutral o. 1. an arrangement of teeth such that the maxillary and mandibular first permanent molars are in normal anteroposterior relation;normal o. (2); 2. neutroclusion
normal o. 1. that arrangement of teeth and their supporting structure which is usually found in health and which approaches an ideal or standard arrangement;normal bite; 2. neutral o. (1)
pathogenic o. an occlusal relationship capable of producing pathologic changes in the supporting tissues.
physiologic o. o. in harmony with functions of the masticatory system.
physiologically balanced o. a balanced o. that is in harmony with the temporomandibular joints and the neuromuscular system.
posterior o. the most effective contact of the molar and bicuspid teeth of both jaws which allows for all the natural movements of the jaws essential to normal mastication and closure.posteroclusion;
postnormal o. distal o. (1)
protrusive o. o. which results when the mandible is protruded forward from centric position.
o. of pupil the presence of an opaque membrane closing the pupillary area.
retrusive o. 1. a biting relationship in which the mandible is forcefully or habitually placed more distally than the patient's centric o.; 2. distal o. (1)
spherical form of o. an arrangement of teeth which places their occlusal surfaces on the surface of an imaginary sphere (usually 8 inches in diameter) with its center above the level of the teeth. See also Monson curve.
torsive o. torsiversion
traumatic o. traumatogenic o
traumatogenic o. a malocclusion capable of producing injury to the teeth and/or associated structures.traumatic o;
working o. working contacts, under contact



Copyright© 1995 Williams & Wilkins. All rights reserved.

occlusive occlusive (o-klu´siv)
Serving to close; denoting a bandage or dressing that closes a wound and excludes it from the air.



Copyright© 1995 Williams & Wilkins. All rights reserved.

occlusometer occlusometer (ok-lu-som´e-ter)
gnathodynamometer



Copyright© 1995 Williams & Wilkins. All rights reserved.

occult occult (o-kult´, ok´ult)
1. Hidden; concealed; not manifest. 2. Denoting a concealed hemorrhage, the blood being inapparent or localized to a site where it is not visible. See occult blood. 3. In oncology, a clinically unidentified primary tumor with recognized metastases. [L. oc-culo, pp. -cultus, to cover, hide]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oceanospirillum Oceanospirillum (o´shen-o-spI-ril´um)
A genus of motile, nonsporeforming, aerobic bacteria (family Spirillaceae) containing Gram-negative, rigid, helical cells which are 0.3 to 1.2 mum in diameter. Motile cells contain bipolar fascicles of flagella. There is no growth anaerobically with nitrate. These organisms are chemoorganotrophic and possess a strictly respiratory metabolism; they neither oxidize nor ferment carbohydrates; found in marine environments. There are at present five species in this genus, of which the type species is O. linum. [L. oceanus, ocean, + spirillum, coil]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ocellus ocellus, pl. ocelli (o-sel´us, -lI)
1. The simple eye found in many invertebrates.eyespot (2); 2. Facet of the compound eye of an insect. [L. dim. of oculus, eye]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ochlophobia ochlophobia (ok-lo-fo´be-a)
Morbid fear of crowds. [G. ochlos, a crowd, + phobos, fear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ochoa Ochoa
Severo, Spanish-U.S. biochemist and Nobel laureate, *1905. See O.'s law.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ochoa's law Ochoa's law
See under law.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ochratoxins ochratoxins (o-kra-toks´ins)
Mycotoxins produced by Aspergillus ochraceus during food spoilage.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ochrodermia ochrodermia (o-kro-der´me-a)
Yellow discoloration of the skin. [G. ochros, pale yellow, + derma, skin]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ochrometer ochrometer (o-krom´e-ter)
An instrument for determining the capillary blood pressure; one of two adjacent fingers is compressed by a rubber balloon until blanching of the skin occurs, after which the force necessary to accomplish this color change is read in millimeters of mercury. [G. ochros, pale yellow, + metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ochronosis ochronosis (o-kron-o´sis)
A pathologic condition observed in certain persons with alkaptonuria, characterized by pigmentation of the cartilages and sometimes tissues such as muscle, epithelial cells, and dense connective tissue; may affect also the sclera, mucous membrane of the lips, and skin of the ears, face, and hands, and cause standing urine to be dark-colored and contain pigmented casts; pigmentation is thought to result from oxidized homogentisic acid, and cartilage degeneration results in osteoarthritis, particularly of the spine. [G. ochros, pale yellow, + nosos, disease]
exogenous o. pigmentation of the skin of the face and elsewhere from prolonged topical exposure to hydroquinone-containing bleaching creams.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ochronotic ochronotic (o-kron-ot´ik)
Relating to or characterized by ochronosis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ochsner Ochsner
Albert J., U.S. surgeon, 1858-1925. See O. clamp; O.'s method.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ocrylate ocrylate (ok´ri-lat)
Octyl-2-cyanoacrylate;a tissue adhesive for surgery.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oct- oct- , octi- , octo- , octa-
Eight. [G. okto, L. octo]



Copyright© 1995 Williams & Wilkins. All rights reserved.

OCTA OCTA (ok´ta)
An eight-base pair sequence in DNA that has a regulatory role; for example, if it is artificially appended to a gene, it will cause that gene to be preferentially expressed in cells of the beta-lymphocyte lineage.



Copyright© 1995 Williams & Wilkins. All rights reserved.

octacosanoic acid octacosanoic acid (ok-ta-ko´san-o-ik)
CH3-(CH2)26-COOH;a long-chain fatty acid; found in waxes.montanic acid;



Copyright© 1995 Williams & Wilkins. All rights reserved.

octad octad (ok´tad)
1. octavalent 2. An octavalent element or radical. [L. octo, eight]



Copyright© 1995 Williams & Wilkins. All rights reserved.

octamethyl pyrophosphoramide (OMPA) octamethyl pyrophosphoramide (OMPA) (ok-ta-meth´il pI´ro-fos-for´a-mId)
schradan



Copyright© 1995 Williams & Wilkins. All rights reserved.

octamylamine octamylamine (ok-ta-mil´a-men)
N-Isopentyl-1,5-dimethylhexylamine;an anticholinergic agent.



Copyright© 1995 Williams & Wilkins. All rights reserved.

octan octan (ok´tan)
Applied to fever, the paroxysms of which recur every eighth day, the day of a paroxysm being counted as the first in the computation. [L. octo, eight]



Copyright© 1995 Williams & Wilkins. All rights reserved.

octandioic acid octandioic acid
suberic acid



Copyright© 1995 Williams & Wilkins. All rights reserved.

octanoate octanoate (ok´ta-no-at)
caprylate



Copyright© 1995 Williams & Wilkins. All rights reserved.

octanoic acid octanoic acid (ok´ta-no-ik)
caprylic acid



Copyright© 1995 Williams & Wilkins. All rights reserved.

octanoyl-CoA synthetase octanoyl-CoA synthetase (ok´tan-o-il sin-the-tas)
butyrate-CoA ligase



Copyright© 1995 Williams & Wilkins. All rights reserved.

octapeptide octapeptide (ok-ta-pep´tId)
A peptide made up of eight amino acid residues.



Copyright© 1995 Williams & Wilkins. All rights reserved.

octaploidy octaploidy (ok´ta-ploy´de)
See polyploidy.



Copyright© 1995 Williams & Wilkins. All rights reserved.

octapressin octapressin (ok-ta-pres´in)
felypressin



Copyright© 1995 Williams & Wilkins. All rights reserved.

octavalent octavalent (ok´ta-va´lent, ok-tav´a-lent)
Denoting a chemical element or radical having a combining power (valency) of eight.octad (1);



Copyright© 1995 Williams & Wilkins. All rights reserved.

octavus octavus (ok-ta´vus)
vestibulocochlear nerve [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

octi- octi-
See oct-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

octo- octo-
See oct-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Octomitidae Octomitidae (ok-to-mit´i-de)
A family in the protozoan class Zoomastigophorea; flagellates with six to eight flagella arranged in pairs and a body that is bilaterally symmetric; it includes the common human intestinal parasite G. lamblia. [octo- + G. mitos, thread]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Octomitus hominis Octomitus hominis (ok-tom´i-tus hom´i-nis)
Pentatrichomonas hominis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

octopamine octopamine (ok-to´pa-men)
a-(aminomethyl)-p-hydroxybenzyl alcohol;a sympathomimetic amine; a false neurotransmitter produced by noradrenergic neurons in the presence of monoamine oxidase inhibitors.norsympatol, norsynephrine;



Copyright© 1995 Williams & Wilkins. All rights reserved.

octose octose (ok´tos)
A sugar containing eight carbon atoms.



Copyright© 1995 Williams & Wilkins. All rights reserved.

octoxynol octoxynol (ok-tok´si-nol)
Polyethylene glycol mono[p-(1,1,3,3,-tetramethylbutyl)phenyl]ether;a surfactant.



Copyright© 1995 Williams & Wilkins. All rights reserved.

octulose octulose (ok´tu-los)
An eight-carbon monoketose.



Copyright© 1995 Williams & Wilkins. All rights reserved.

octulosonic acid octulosonic acid (ok´tu-lo-son´ik)
The -onic acid formally formed by oxidation of carbon atom 1 of octulose to a carboxylic acid group; a condensation product of d-arabinose and phosphoenolpyruvate analogous to neuraminic acid. It forms part of the repeating unit of the polysaccharides of the complex lipopolysaccharides of the Enterobacteriaceae constituting the characteristic somatic octose antigens.



Copyright© 1995 Williams & Wilkins. All rights reserved.

octyl gallate octyl gallate (ok´til gal´at)
Octyl 3,4,5-trihydroxybenzoate;an antioxidant.



Copyright© 1995 Williams & Wilkins. All rights reserved.

octylphenoxy polyethoxyethanol octylphenoxy polyethoxyethanol (ok´til-fe-nok´se pol´e-eth-ok´se-eth´a-nol)
Mono-p-isooctyl phenyl ether of polyethylene glycol; a surface-active (wetting) agent.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ocular ocular (ok´yu-lar)
1. ophthalmic 2. The eyepiece of a microscope, the lens or lenses at the observer end of a microscope, by means of which the image focused by the objective is viewed. [L. oculus, eye]
compensating o. an o. that compensates and corrects for the effects of chromatic aberration in the objective.
Huygens' o. the compound o. of a microscope, composed of two planoconvex lenses so arranged that the plane side of each is directed toward the observer.
o. motor relating to or causing movements of the eyeball.
Ramsden's o. an eyepiece of a microscope, consisting of two planoconvex lenses with convexities turned to each other.
wide field o. an o. that gives a larger than usual field of view and a high eyepoint.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ocularist ocularist (ok´yu-lar-ist)
One skilled in the design, fabrication, and fitting of artificial eyes and the making of prostheses associated with the appearance or function of the eyes. [L. oculus, eye]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculentum oculentum, pl. oculenta (ok-yu-len´tum, -ta)
ophthalmic ointment [Mod. L., fr. L. oculus, eye]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculi oculi (ok´yu-lI)
Plural of oculus. [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculist oculist (ok´yu-list)
ophthalmologist [L. oculus, eye]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculo- oculo-
The eye, ocular. See also ophthalmo-. [L. oculus]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculoauriculovertebral oculoauriculovertebral (ok´yu-lo-aw-rik´yu-lo-ver´te-bral)
Relating to the eyes, ears, and vertebrae.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculocardiac oculocardiac (ok´yu-lo-kar´de-ak)
Relating to the eyes and heart.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculocerebrorenal oculocerebrorenal (ok´yu-lo-ser´e-bro-re´nal)
Relating to the eyes, brain, and kidneys.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculocutaneous oculocutaneous (ok´yu-lo-kyu-ta´ne-us)
Relating to the eyes and the skin.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculodentodigital oculodentodigital (ok´yu-lo-den´to-dij´i-tal)
Relating to the eyes, teeth, and fingers.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculodermal oculodermal (ok´yu-lo-der´mal)
Relating to the eyes and skin.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculodynia oculodynia
Pain in the eyeball.ophthalmalgia; [ophthalmo- + G. algos, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculofacial oculofacial (ok-yu-lo-fa´shal)
Relating to the eyes and the face.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculography oculography (ok-yu-log´ra-fe)
A method of recording eye position and movements. [oculo- + G. graphe, a writing]
photosensor o. o. in which photocells are directed to the surface of the eye to record rotations.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculogyria oculogyria (ok´yu-lo-jI´re-a)
The limits of rotation of the eyeballs. [oculo- + G. gyros, circle]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculogyric oculogyric (ok´yu-lo-jI´rik)
Referring to rotation of the eyeballs; characterized by oculogyria.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculomandibulodyscephaly oculomandibulodyscephaly (ok´yu-lo-man-dib´yu-lo-dis-sef´a-le)
dyscephalia mandibulo-oculofacialis



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculomotor oculomotor (ok´yu-lo-mo´tor)
Pertaining to the o. cranial nerve. [L. oculomotorius, fr. oculo- + L. motorius, moving]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculomotorius oculomotorius (ok´yu-lo-mo-to´re-us)
oculomotor nerve [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculonasal oculonasal (ok´yu-lo-na´sal)
Relating to the eyes and the nose. [oculo- + L. nasus, nose]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculopathy oculopathy (ok-yu-lop´a-the)
ophthalmopathy



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculoplethysmography oculoplethysmography (ok´yu-lo-pleth-iz-mog´ra-fe)
Indirect measurement of the hemodynamic significance of internal carotid artery stenosis or occlusion by demonstration of an ipsilateral delay in the arrival of ocular pressure transmitted from branches of the ophthalmic artery. [oculo- + G. plethymos, increase, + graphe, to write]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculopneumoplethysmography oculopneumoplethysmography (ok´yu-lo-nu´mo-pleth-iz-mog´ra-fe)
A method of bilateral measurement of ophthalmic artery pressure that reflects pressure and flow in the internal carotid artery. See oculoplethysmography.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculopupillary oculopupillary (ok´yu-lo-pu´pi-lar-e)
Pertaining to the pupil of the eye.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculosympathetic oculosympathetic (ok´u-lo-sim-pa-the´tik)
Pertaining to the sympathetic pathway to the eye, damage to which produces Horner's syndrome.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculovertebral oculovertebral (ok´yu-lo-ver´te-bral)
Relating to the eyes and vertebrae.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculozygomatic oculozygomatic (ok´yu-lo-zI-go-mat´ik)
Relating to the orbit or its margin and the zygomatic bone.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oculus oculus, gen and pl. oculi (ok´yu-lus, -lI) [NA]
eye (1) [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ocy- ocy-
See oxy-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ocytocin ocytocin (o-si-to´sin)
oxytocin [G. okytokos, fast birth, prompt delivery]



Copyright© 1995 Williams & Wilkins. All rights reserved.

OD OD
Abbreviation for overdose; optical density (see absorbance).



Copyright© 1995 Williams & Wilkins. All rights reserved.

O.D. O.D.
Abbreviation for L. oculus dexter, right eye. 2. Abbreviation for Doctor of Optometry. See optometrist.



Copyright© 1995 Williams & Wilkins. All rights reserved.

o.d. o.d.
Abbreviation for L. omni die, every day.



Copyright© 1995 Williams & Wilkins. All rights reserved.

od od
A force assumed to be exerted upon the nervous system by magnets. [G. hodos, way]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odaxesmus odaxesmus (o´dak-sez´mus)
A biting sensation; a form of paresthesia. [G. odaxesmos, an irritation, fr. odax (adv.), by biting.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odaxetic odaxetic (o´dak-set´ik)
1. Causing formication or itching. 2. A substance or agent that causes formication or itching. [G. odaxesmos, an irritation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oddi Oddi
Ruggero, Italian physician; 1864-1913. See O.'s sphincter.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odditis odditis (od-I´tis)
Inflammation of the junction of the duodenum and common bile duct at the sphincter of Oddi.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odds odds
The ratio of probability of occurrence to non-occurrence of an event. [pl. of odd, fr. M.E. odde, fr. O.Norse oddi, odd number]



Copyright© 1995 Williams & Wilkins. All rights reserved.

-odes -odes
Having the form of, resembling. [G. eidos, form, resemblance]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Odland body Odland body
See under body.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odogenesis odogenesis (o-do-jen´e-sis)
neurocladism [G. hodos, path, + genesis, source]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odont- odont- , odonto-
A tooth, teeth (properly used in words formed from G. roots). [G. odous (odont-)]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontagra odontagra (o-don-tag´ra)
Obsolescent term for toothache thought to be of gouty origin. [odonto- + G. agra, seizure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontalgia odontalgia (o-don-tal´je-a)
toothache [odont- + G. algos, pain]
o. denta´lis reflex pain in the ear due to dental disease, usually propagated along the auriculotemporal nerve.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontalgic odontalgic (o-don-tal´jik)
Relating to or marked by toothache.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontectomy odontectomy (o-don-tek´to-me)
Removal of teeth by the reflection of a mucoperiosteal flap and excision of bone from around the root or roots before the application of force to effect the tooth removal. [odont- + G. ektome, excision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odonterism odonterism (o-don´ter-izm)
Chattering of the teeth. [odont- + G. erismos, quarrel]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontiasis odontiasis (o-don-tI´a-sis)
teething



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontinoid odontinoid (o-don´ti-noyd)
1. Resembling dentin. 2. A small excrescence from a tooth, most common on the root or neck. 3. Toothlike.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontitis odontitis (o-don-tI´tis)
pulpitis



Copyright© 1995 Williams & Wilkins. All rights reserved.

odonto- odonto-
See odont-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoameloblastoma odontoameloblastoma (o-don´to-am´e-lo-blas-to´ma)
ameloblastic odontoma



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoblast odontoblast (o-don´to-blast)
One of the dentin-forming cells, derived from mesenchyme of neural crest origin, lining the pulp cavity of a tooth; o.'s are arranged in a peripheral layer in the dental pulp, forming the dentinal matrix, with odontoblastic processes extending from each cell into a dentinal tubule; the cells generally are columnar in the coronal pulp but are more cuboidal in the radicular area and adjacent to tertiary dentin. [odonto- + G. blastos, sprout, germ]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoblastoma odontoblastoma (o-don´to-blas-to´ma)
1. A tumor composed of neoplastic epithelial and mesenchymal cells that may differentiate into cells able to produce calcified tooth substances. 2. An odontoma in its early formative stage. [odontoblast + G. -oma, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoclast odontoclast (o-don´to-klast)
One of the cells believed to produce resorption of the roots of the deciduous teeth. [odonto- + G. klastos, broken]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontodynia odontodynia (o-don-to-din´e-a)
toothache [odonto- + G. odyne, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontodysplasia odontodysplasia (o-don´to-dis-pla´ze-a)
A developmental disturbance of one or of several adjacent teeth, of unknown etiology, characterized by deficient formation of enamel and dentin which results in an abnormally large pulp chamber and imparts a ghostlike radiographic image to the teeth; such teeth exhibit delayed eruption into the oral cavity.odontogenesis imperfecta, odontogenic dysplasia;



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontogenesis odontogenesis (o-don-to-jen´e-sis)
The process of development of the teeth.odontogeny, odontosis; [odonto- + G. genesis, production]
o. imperfec´ta odontodysplasia



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontogeny odontogeny (o-don-toj´e-ne)
odontogenesis



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoid odontoid (o-don´toyd)
1. Shaped like a tooth.dentoid; 2. Relating to the toothlike o. process of the second cervical vertebra. [odont- + G. eidos, resemblance]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontology odontology (o-don-tol´o-je)
dentistry [odonto- + G. logos, study]
forensic o. forensic dentistry



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoloxia odontoloxia , odontoloxy (o-don-to-lok´se-a, o-don-tol´ok-se)
odontoparallaxis [odonto- + G. loxos, slanting]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontolysis odontolysis (o-don-tol´i-sis)
erosion (3) [odonto- + G. lysis, dissolution]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoma odontoma (o-don-to´ma)
1. A tumor of odontogenic origin. 2. A hamartomatous odontogenic tumor comprised of enamel, dentin, cementum, and pulp tissue that may or may not be arranged in the form of a tooth. [odonto- + G. -oma, tumor]
ameloblastic o. a benign mixed odontogenic tumor comprised of an undifferentiated component histologically identical to an ameloblastoma and a well differentiated component identical to an odontoma; appears as a mixed radiolucent-radiopaque lesion and presents clinically as an ameloblastoma.odontoameloblastoma;
complex o. an o. in which the various odontogenic tissues are organized in a haphazard arrangement with no resemblance to teeth.
compound o. an o. in which the odontogenic tissues are organized and resemble anomalous teeth.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoneuralgia odontoneuralgia (o-don´to-nu-ral´je-a)
Facial neuralgia caused by a carious tooth.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontonomy odontonomy (o-don-ton´o-me)
Dental nomenclature. [odonto- + G. onoma, name]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontonosology odontonosology (o-don´to-no-sol´o-je)
dentistry [odonto- + G. nosos, disease, + logos, study]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoparallaxis odontoparallaxis (o-don´to-par-a-lak´sis)
Irregularity of the teeth.odontoloxia, odontoloxy; [odonto- + G. parallax, alternately]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontopathy odontopathy (o-don-top´a-the)
Any disease of the teeth or of their sockets. [odonto- + G. pathos, suffering]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontophobia odontophobia (o-don-to-fo´be-a)
Morbid fear of teeth. [odonto- + G. phobos, fear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoplasty odontoplasty (o-don´to-plas-te)
Surgical contouring of tooth surface to enhance plaque control and gingival morphology. [odonto- + G. plasso, to mold]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoprisis odontoprisis (o-don-top´ri-sis)
Grinding together of the teeth. See also bruxism. [odonto- + G. prisis, a sawing, a grinding]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoptosis odontoptosis (o-don-top-to´sis, -to-to´sis)
Downward movement of an upper tooth due to the loss of its lower antagonist(s). See also supereruption. [odonto- + G. ptosis, a falling]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontorrhagia odontorrhagia (o-don-to-ra´je-a)
Profuse bleeding from the socket after the extraction of a tooth. [odonto- + G. rhegnymi, to burst forth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoschism odontoschism (o-don´to-skizm, -sizm)
Fissure of a tooth. [odonto- + G. schisma, a cleft]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoscope odontoscope (o-don´to-skop)
An optical device, similar to a closed circuit television system, that projects a view of the oral cavity onto a screen for multiple viewing.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontoscopy odontoscopy (o-don-tos´ko-pe)
1. Examination of the oral cavity by means of the odontoscope. 2. Examination of the markings in prints of the cutting edges of the teeth; used, like fingerprints, as a method of personal identification. [odonto- + G. skopeo, to view]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontosis odontosis (o-don-to´sis)
odontogenesis



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontotherapy odontotherapy (o-don-to-thar´a-pe)
Treatment of diseases of the teeth.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odontotomy odontotomy (o-don-tot´o-me)
Cutting into the crown of a tooth. [odonto- + G. tome, incision]
prophylactic o. a preventive operation in which imperfectly formed developmental grooves, pits, and fissures are opened up by means of a bur and filled in order to obviate future decay.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odor odor (o´dor)
Emanation from any substance that stimulates the olfactory cells in the organ of smell.scent, smell (3); [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odorant odorant (o´dor-ant)
A substance with an odor.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odoratism odoratism (o-dor´a-tizm)
See lathyrism, osteolathyrism. [fr. Lathyrus odoratus, sweet pea]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odoriferous odoriferous (o-do-rif´er-us)
Having a scent, perfume, or odor.odorous; [odor + L. fero, to bear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odorimeter odorimeter (o´do-rim´e-ter)
Instrument for performing odorimetry.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odorimetry odorimetry (o´do-rim´e-tre)
The determination of the comparative power of different substances in exciting olfactory sensations. [odor + G. metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odorivection odorivection (o´dor-i-vek´shun)
Conveying or bearing an odor, as on the air. [odor + L. vector, a carrier]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odorography odorography (o´do-rog´ra-fe)
Description of odors. [odor + G. graphe, a description]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odorous odorous (o´dor-us)
odoriferous



Copyright© 1995 Williams & Wilkins. All rights reserved.

O'Dwyer O'Dwyer
Joseph P., U.S. physician, 1841-1898. See O'D.'s tube.



Copyright© 1995 Williams & Wilkins. All rights reserved.

odyn- odyn- , odyno-
Pain. [G. odyne]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odynacusis odynacusis (o-din´a-ku´sis)
Hypersensitiveness of the organ of hearing, so that noises cause actual pain. [odyn- + G. akouo, to hear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odynometer odynometer (o-di-nom´e-ter)
algesiometer [odyno- + G. metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odynophagia odynophagia (o-din-o-fa´je-a)
Pain on swallowing. [odyno- + G. phago to eat]



Copyright© 1995 Williams & Wilkins. All rights reserved.

odynophonia odynophonia (o-din-o-fo´ne-a)
Pain on using the voice. [odyno- + G. phone, sound, voice]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oe Oe
Symbol for oersted.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oe- oe-
For words so beginning and not found here, see e-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oedipism oedipism (ed´i-pizm)
1. Self-infliction of injury to the eyes, usually an attempt at evulsion. 2. Manifestation of the Oedipus complex. [Oedipus, G. myth. char.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oehl Oehl
Eusebio, Italian anatomist, 1827-1903. See O.'s muscles, under muscle.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oehler Oehler
Johannes, German physician, *1879. See O.'s symptom.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oenanthal oenanthal (e-nan´thal)
heptanal



Copyright© 1995 Williams & Wilkins. All rights reserved.

oersted (Oe) oersted (Oe) (er´sted)
A unit of magnetic field intensity; the magnetic field intensity that exerts a force of 1 dyne on unit magnetic pole; equal to (1000/4pi) A. m-1. [Hans-Christian Oersted Danish physicist, 1777-1851]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oesophagostomiasis oesophagostomiasis ( e-sof´a-go-sto-mI´a-sis)
Infection with nematode parasites of the genus Oesophagostomum.esophagostomiasis; [G. oi-sophagos, gullet (esophagus), + stoma, mouth, + -iasis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oesophagostomum Oesophagostomum (e-sof-a-gos´to-mum)
A genus of strongyle nematodes (subfamily Oesophagostominae) that encyst in the intestinal wall of herbivores and primates, causing nodular disease. Larvae appear to stimulate a host reaction in the intestinal wall, forming nodules in which the worms complete their development (unless the host is immune); they then leave the nodule and feed as adults in the lumen of the large intestine. [G. oisophagos, gullet (esophagus), + stoma, mouth]
O. apios´tomum a primate species that has been reported in northern Nigeria and central Africa to encyst under the submucosa of the human intestine and occasionally cause dysentery; a common parasite of monkeys and apes, both in captivity and in the wild.
O. brevicau´dum a species that occurs in the cecum and colon of pigs in North America and India.
O. brump´ti a species described from African monkeys and reported occasionally in humans.
O. columbia´num a species that occurs in sheep, goats, and wild African antelopes; except when present in large numbers, it does not appear to seriously affect the health of the host.
O. denta´tum a species that affects the colon of swine; the lesions are similar to those in sheep.
O. georgia´num a species that occurs in the cecum and colon of pigs in the U.S.
O. quadrispinula´tum a species that occurs in the cecum and colon of pigs in the Americas, Europe, and Southeast Asia.
O. radia´tum a species that occurs worldwide in cattle and water buffalo; the lesions are similar to those of sheep.
O. stephanos´tomum a species occurring in chimpanzees, monkeys, and gorillas in Africa, but also reported from humans and monkeys in Brazil.
O. venulo´sum a species that occurs worldwide in the cecum and colon of cattle, sheep, goats, deer, and many other ruminants.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oestradiol oestradiol (es-tra-dI´ol)
estradiol



Copyright© 1995 Williams & Wilkins. All rights reserved.

oestrids oestrids (est´ridz)
Common name for botflies of the family Oestridae, such as Oestrus. [G. oistros, gadfly]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oestriol oestriol (es´tre-ol)
estriol



Copyright© 1995 Williams & Wilkins. All rights reserved.

oestrogen oestrogen (es´tro-jen)
estrogen



Copyright© 1995 Williams & Wilkins. All rights reserved.

oestrone oestrone (es´tron)
estrone



Copyright© 1995 Williams & Wilkins. All rights reserved.

oestrosis oestrosis (es-tro´sis)
Infection of small ruminants and rarely humans with larvae of the fly Oestrus ovis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oestrus Oestrus (es´tus)
A genus of tissue-invading flies that cause myiasis in sheep; the head botflies in the family Oestridae. O. ovis (a nose fly) is a grayish brown, robust, hairy, beelike botfly, imported from Europe, and now a serious pest in parts of the U.S.; larvae are deposited by the adult fly in the nostrils of sheep, and inch-long larvae develop in the paranasal sinuses, causing considerable mucous discharge and distress in old or weak sheep. [G. oistros, gadfly]



Copyright© 1995 Williams & Wilkins. All rights reserved.

official official (o-fish´al)
Authoritative; denoting a drug or a chemical or pharmaceutical preparation recognized as standard in the pharmacopeia. Cf. officinal. [L. officialis, fr. officium, a favor, service, fr. opus, work, + facio, to do]



Copyright© 1995 Williams & Wilkins. All rights reserved.

officinal officinal (o-fis´i-nal)
Denoting a chemical or pharmaceutical preparation kept in stock, in contrast to magistral (prepared extemporaneously according to a physician's prescription); an o. preparation is often, though not necessarily, official. [L. officina, shop]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ogino Ogino
Kyusaka, 20th century Japanese physician. See O.-Knaus rule.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ogston Ogston
Sir Alexander, Scottish surgeon, 1844-1929. See O.'s line; O.-Luc operation.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oguchi Oguchi
Chita, Japanese ophthalmologist, 1875-1945. See O.'s disease.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ogura Ogura
Joseph H., U.S. otolaryngologist, *1915. See O. operation.



Copyright© 1995 Williams & Wilkins. All rights reserved.

O'Hara O'Hara
Michael, Jr., U.S. surgeon, 1869-1926. See O'H. forceps.



Copyright© 1995 Williams & Wilkins. All rights reserved.

OHI OHI
Abbreviation for Oral Hygiene Index.



Copyright© 1995 Williams & Wilkins. All rights reserved.

OHI-S OHI-S
Abbreviation for Simplified Oral Hygiene Index.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ohm (OMEGA) Ohm (OMEGA)
Georg S., German physicist, 1787-1854. See ohm; O.'s law.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ohm ohm (om)
The practical unit of electrical resistance; the resistance of any conductor allowing 1 ampere of current to pass under the electromotive force of 1 volt. [G.S. Ohm]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ohmammeter ohmammeter (om-am´e-ter)
A combined ohmmeter and ammeter.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ohmmeter ohmmeter (om´e-ter)
An instrument for determining the resistance, in ohms, of a conductor.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ohne Hauch ohne Hauch (o´na howch)
Term used to designate the nonspreading growth of nonflagellated bacteria on agar media; also applied to somatic agglutination. See also O antigen. [Ger. without breath]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ohngren's line Ohngren's line
See under line.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oi- oi-
For words so beginning and not found here, see e-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

-oid -oid
Resemblance to, joined properly to words formed from G. roots; equivalent to Eng. -form. [G. eidos, form, resemblance]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oidia oidia (o-id´ea)
Plural of oidium.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oidiomycin oidiomycin (o-id´e-o-mI´sin)
An antigen used to demonstrate cutaneous hypersensitivity in patients infected with one of the Candida species; one of a series of antigens used to demonstrate an immunocompromised patient's capacity to react to any cutaneous antigen. [oidium + G. mykes, fungus, + -in]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oidium oidium, pl. oidia (o-id´e-um, o-id´e-a)
Formerly used term for arthroconidium. [Mod. L. dim. of G. oon, egg]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oil oil (oyl)
An inflammable liquid, of fatty consistence and unctuous feel, that is insoluble in water, soluble or insoluble in alcohol, and freely soluble in ether. O.'s are variously classified as animal, vegetable, and mineral o.'s according to their source (the mineral o.'s probably being of remote animal and vegetable origin); into fatty (fixed) and volatile o.'s; and into drying and nondrying (fatty) o.'s, the former becoming gradually thicker when exposed to the air and finally drying to a varnish, the latter not drying but liable to become rancid on exposure. Many of the o.'s, both fixed and volatile, are used in medicine. For individual o.'s, see the specific names. [L. oleum; G. elaion, originally olive oil]
absolute o.'s essential o.'s that are obtained by the removal of insoluble compounds from concrete oils.
o. of anise volatile o. derived from the dried ripe fruit of Pimpinella anisum (family Umbelliferae) or of Illicium verum, (family Magnoliaceae) (Chinese star anise); has a characteristic anise aroma, resembling fennel. Used in manufacture of liqueurs, and as flavoring for candies, cookies, dentifrices. Pharmaceutical aid (flavor). Carminative.
o. of bay volatile o. derived by steam distillation of the dried leaves of Pimenta (Myrcia) acris (family Myrtaceae); o. of myrcia; used as an aromatic in the manufacture of bay rum and as a pharmaceutical aid.
o. of bergamot volatile o. derived by steam distillation from the rind of the fresh fruit of Citrus aurantium or C. bergamia; contains l-linalyl acetate, l-linalool; d-limonene, dipentene, bergaptene; used as a deodorant in preparations containing malodorous ingredients and as an aromatic in perfumes, hairdressings, and pomades.
betula oil (bet´yu-la) oil of sweet birch, a volatile oil obtained by distillation from the bark of Betula lenta (sweet birch); used as a flavoring agent and as a counterirritant liniment. See also methyl salicylate.
o. of bitter almond volatile o. from the dried ripe kernels of bitter almonds or from other kernels containing amygdalin, such as apricots, peaches, plums and cherries; obtained by steam distillation subsequent to maceration of the source with water. Formerly used as an antipruritic; poisonous-releases hydrocyanic acid (hydrogen cyanide). Only the oil free of hydrogen cyanide may be used to flavor liquors and foods.
o. of bitter orange volatile o. obtained by steam distillation from the fresh peel of Citrus aurantium (family Rutaceae). Aromatic material used as a flavoring agent in pharmaceuticals and foods and liquors; also used in perfumes.
o. of cardamom volatile o. obtained by steam distillation from the seeds of Elettaria cardamomum (family Zingiberacea.) A flavoring agent in pharmaceuticals (syrups), liquors, sauces, confections and baked goods; formerly used as a carminative.
o. of chenopodium volatile o. from the fresh above ground part of the flower, American wormseed, Chenopodium ambrosioides, or C. anthelminticum. Used as an anthelmintic.oil of American o;
o. of cherry laurel volatile o. derived by steam distillation from Prunus laurocerasus (family Rosaceae); similar to o. of bitter almond; highly toxic due to hydrogen cyanide content.
o. of cinnamon volatile o. obtained by steam distillation from the leaves and twigs of Cinnamomum cassia (family Lauracea). A flavor in foods and perfumes.
o. of citronella volatile o. obtained by steam distillation of fresh lemon grass. Contains citranellol; used as an insect repellent either on the skin or in the form of incense; also used as a perfume.
o. of clove volatile o. obtained by steam distillation of the dried flower buds of Eugenia caryophyllata (family Myrtacea). Contains about 85% eugenol along with other constituents. Used in dentistry as a local anesthetic and component of temporary fillings of the teeth. Also used to flavor foods; strong, pungent odor.clove oil;
concrete o.'s essential o.'s obtained by extraction with organic solvents; contain waxes and paraffins.
o. of coriander volatile o. from the dried ripe fruit of Coriandrum sativum (family Umbelliferae). Flavoring in foods and alcoholic beverages.
o. of cubeb volatile o. of the unripe fruit of Piper cubeba (family Piperaceae). Formerly used as a urinary antiseptic.
o. of dwarf pine needles volatile o. from the fresh leaves of Pinus montana (family Pinaceae). Pleasant pine odor; used as a pharmaceutical aid (flavor and perfume). Has been used as an expectorant.
essential o.'s plant products, usually somewhat volatile, giving the odors and tastes characteristic of the particular plant, thus possessing the essence, e.g., citral, pinene, camphor, menthane, terpenes; usually, the steam distillates of plants or oils of plants obtained by pressing out the rinds of a particular plant. See also volatile o.
ethereal o. volatile o
o. of eucalyptus volatile o. from the fresh leaves of Eucalyptus globulus (family Myrtaceae) and some other species of Eucalyptus; native to Australia; pungent o. with a spicy, cooling taste. Has been used as an aromatic in inhalants, as an expectorant, anthelmintic, and local antiseptic.
fatty o. an o. derived from both animals and plants; chemically, a glyceride of a fatty acid which, by substitution of the glycerine by an alkaline base, is converted into a soap; a fatty o., in contrast to a volatile o., is permanent, leaving a stain on an absorbent surface, and thus is not capable of distillation; it is obtained by expression or extraction; the consistency varies with the temperature, some being liquid (o.'s proper), others semisolid (fats), and others solid (tallows) at ordinary temperatures; both liquid and semisolid o.'s are congealed by cold and the solids are liquified by heat.fixed o;
o. of fennel volatile o. from the dried fruit of Foeniculum vulgare (family Umbelliferae). An aromatic o. with the odor and taste of fennel, similar to anise; used as a flavoring agent in pharmaceuticals. Has been used as a carminative.
fixed o. fatty o
fusel o. a mixture of side products of alcoholic fermentation; consists primarily of alcohols (e.g., amyl, propyl, isoamyl, and isobutyl alcohols).
joint o. synovial fluid
jojoba o. a liquid wax ester mixture extracted from ground or crushed seeds from Simmondsia chinensis and S. californica (family Buxaceae), desert shrubs native to Arizona, California, and northern Mexico. Used extensively in cosmetics for alleged skin softening and lubricating properties; other uses include as lubricant, fuel, chemical feedstock, substitute for sperm whale oil.oil of jojoba;
o. of juniper volatile o. from the dried ripe fruit (berries) of Juniperus communis (family Cupressaceae). Formerly used as a diuretic. Used in perfumery.juniper berry oil;
o. of lavender volatile o. from fresh flowering tops of Lavandula officinalis (family Labiatae). Aromatic o. used in perfume and as a flavoring agent. Has been used as a carminative.
o. of lemon volatile o. expressed from fresh peel of Citrus limonum (family Rutaceae). Aromatic o. used for flavoring pharmaceuticals, liqueurs, pastry, foods, beverages, and in perfumes.
o. of lemon grass volatile o. from Cymbopogon citratus and of C. flexuosus (family Gramineae). Used in perfumery and as a source of citral for the synthesis of vitamin A.
oil of American o. o. of chenopodium
oil of crispmint o. of spearmint
oil of curled mint o. of spearmint
oil of jojoba jojoba o
palm o. an o. obtained from the seeds of Elaeis guineensis (family Palmae); used in the manufacture of soap, liniments, and ointments; also in foods.
o. of pennyroyal either American or European. The former is a volatile o. derived from the flowering tops and leaves of Hedeoma pulegioides (family Labiatae). Contains pulegone and ketones. European is o. of pulegium; a volatile o. from Mentha pulegium (family Labiatae); about 85% pulegone. Has been used as an aromatic carminative, abortifacient and insect repellent.
o. of peppermint a volatile o. containing menthol (not less than 50% of total) obtained by steam distillation from the fresh flowering plant Mentha piperita (family Labiatae). Used as a pharmaceutical aid (flavor) and in flavoring liqueurs; a carminative.
o. of rose a volatile o. from the fresh flowers of Rosa gallica and R. damascena and other members of the Rosaceae family. Used largely in perfumery; ointments, and toilet preparations.attar of rose, essence of rose, otto of rose;
o. of spearmint volatile o. from the flowering tops of Mentha spicata (family Labiatae, pharmaceutical aid (flavor) and a carminative.oil of crispmint, oil of curled mint;
sweet birch o. methyl salicylate
o. of turpentine volatile o. distilled from the oleoresin and obtained from Pinus palastrus (family Pinaceae) and other species of Pinus yielding terpene oils. Solvent for o.'s, resins, varnishes; vehicle, thinner and remover of o.-based paints. Rubefacient; has been used as a counterirritant in liniments.
volatile o. a substance of oily consistency and feel, derived from a plant and containing the principles to which the odor and taste of the plant are due (essential o.); in contrast to a fatty o., a volatile o. evaporates when exposed to the air and thus is capable of distillation; it may also be obtained by expression or extraction; many volatile o.'s, identical to or closely resembling the natural o.'s, can be made synthetically. Volatile o.'s are used in medicine as stimulants, stomachics, correctives, carminatives, and for purposes of flavoring (e.g., peppermint oil).ethereal o;
o. of wormwood volatile o. from leaves and tops of Artemisia absinthium (family Compositae). Thujol alcohol and acetate; thujone (a powerful convulsant), phellandrene, cadinene; also a blue o. Used in flavoring of vermouth; formerly in absinthe.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oil red O oil red O [C.I. 26125]
1-8-[4-(Dimethylphenylazo)dimethylphenylazo]-2-naphthalenol;a weakly acid diazo oil-soluble dye, used in histologic demonstration of neutral fats.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oil of vitriol oil of vitriol
sulfuric acid



Copyright© 1995 Williams & Wilkins. All rights reserved.

ointment ointment (oynt´ment)
A semisolid preparation usually containing medicinal substances and intended for external application. O. bases used as vehicles fall into four general classes: 1) Hydrocarbon bases (oleaginous o. bases) keep medicaments in prolonged contact with the skin, act as occlusive dressings, and are used chiefly for emollient effects. 2) Absorption bases either permit the incorporation of aqueous solutions with the formation of a water-in-oil emulsion or are water-in-oil emulsions that permit the incorporation of additional quantities of aqueous solutions; such bases permit better absorption of some medicaments and are useful as emollients. 3) Water-removable bases (creams) are oil-in-water emulsions containing petrolatum, anhydrous lanolin, or waxes; they may be washed from the skin with water, and are thus more acceptable for cosmetic reasons; they favor absorption of serous discharges in dermatological conditions. 4) Water-soluble bases (greaseless ointment bases) contain only water-soluble substances. See also cerate.salve, uncture, unguent; [O. Fr. oignement; L. unguo, pp. unctus, to smear]
blue o. a grease-based o. containing 20% finely divided metallic mercury, formerly widely used for local application to the skin for the destruction of body lice. Risk is associated with transdermal absorption of mercury and a local dermatitis.mild mercurial ointment;
eye o. ophthalmic o
hydrophilic o. an o. base consisting of 25% each of white petrolatum and stearyl alcohol, 12% propyl glycol emulsified in 37% water by 1% of lauryl sulfate; preserved with paraben. Suitable for the incorporation of numerous drugs intended for local application; a washable o. base.
mild mercurial ointment blue o
ophthalmic o. a special o. for application to the eye that must be free from particles and must be nonirritating to the eye.eye o., oculentum;



Copyright© 1995 Williams & Wilkins. All rights reserved.

Okazaki Okazaki
Reiji and Tuneko, 20th century Japanese biochemists. See O. fragment.



Copyright© 1995 Williams & Wilkins. All rights reserved.

-ol -ol
Suffix denoting that a substance is an alcohol or a phenol.



Copyright© 1995 Williams & Wilkins. All rights reserved.

olamine olamine (ol´a-men)
USAN-approved contraction for ethanolamine.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleaginous oleaginous (o-le-aj´i-nus)
Oily or greasy. [L. oleagineus, pertaining to olea, the olive tree]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleander oleander (o-le-an´der)
The bark and leaves of Nerium oleander (family Apocynaceae), a shrub of the eastern Mediterranean; formerly used as a diuretic and heart tonic.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleandomycin phosphate oleandomycin phosphate (o-le-an-do-mI´sin)
An antibiotic substance produced by species of Streptomyces antibioticus; effective against staphylococci, streptococci, pneumococci, and some Gram-negative bacteria.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleate oleate (o´le-at)
1. A salt of oleic acid. 2. A pharmacopeial preparation consisting of a combination or solution of an alkaloid or metallic base in oleic acid, used as an inunction.



Copyright© 1995 Williams & Wilkins. All rights reserved.

olecranon olecranon (o-lek´ra-non, o´le-kra´non) [NA]
The prominent curved proximal extremity of the ulna, the upper and posterior surface of which gives attachment to the tendon of the triceps muscle, the anterior surface entering into the formation of the trochlear notch.elbow bone, olecranon process, point of elbow, tip of elbow; [G. the head or point of the elbow, fr. olene, ulna, + kranion, skull, head]



Copyright© 1995 Williams & Wilkins. All rights reserved.

olefin olefin (o´le-fin)
alkene



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleic acid oleic acid (o-le´ik)
cis-9-Octadecenoic acid;an unsaturated fatty acid that is the most widely distributed and abundant fatty acid in nature; used commercially in the preparation of oleates and lotions, and as a pharmaceutical solvent. Cf. elaidic acid. [L. oleum, oil]



Copyright© 1995 Williams & Wilkins. All rights reserved.

olein olein (o´le-in)
trioleoyl glycerol; glyceryl trioleate;a triacylglycerol, solely containing oleoyl moieties, found in fats and oils.triolein;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleo- oleo-
Oil. See also eleo-. [L. oleum]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleogomenol oleogomenol (o´le-o-go´men-ol)
gomenol



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleogranuloma oleogranuloma (o´le-o-gran-yu-lo´ma)
lipogranuloma



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleoma oleoma (o-le-o´ma)
lipogranuloma



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleometer oleometer (o-le-om´e-ter)
An instrument, similar to a hydrometer, for determining the specific gravity of oils.eleometer; [oleo- + G. metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleopalmitate oleopalmitate (o´le-o-pal´mi-tat)
A double salt of oleic and palmitic acids.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleoresin oleoresin (o´le-o-rez´in)
1. A compound of an essential oil and resin, present in certain plants. 2. A pharmaceutical preparation. See aspidium, capsicum, ginger. 3. balsam



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleosaccharum oleosaccharum, pl. oleosacchara (o´le-o-sak´a-rum)
A class of preparations made by the trituration of a volatile oil (anise, fennel, lemon, etc.) with sugar; used as a diluent or corrigent of powerful or bad tasting drugs in powder form.oil sugar; [oleo- + G. saccharon, sugar]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleostearate oleostearate (o´le-o-ste´a-rat)
A double salt of oleic and stearic acids.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleosus oleosus (o-le-o´sus)
Greasy; relating to abnormality of the sebaceous apparatus. [L., fr. oleum, oil]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleotherapy oleotherapy (o´le-o-thar´a-pe)
Treatment of disease by an oil given internally or applied externally.eleotherapy; [oleo- + G. therapeia, therapy]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleovitamin oleovitamin (o´le-o-vI´ta-min)
A solution of a vitamin in an edible oil.
o. A and D a solution of vitamins A and D in fish liver oil or in an edible vegetable oil.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleum terebinthinae oleum terebinthinae (o´le-um ter-e-ben´thin-I)
turpentine oil



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleyl alcohol oleyl alcohol (o-le´il)
A mixture of aliphatic alcohols consisting chiefly of CH3(CH2)7CH=CH(CH2)7CH2OH; used as an emulsifying aid and in the preparation of cold cream; found in fish oils.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleyl-CoA oleyl-CoA (o-le-il)
A product of the DELTA9-desaturase enzyme system in the biosynthesis of monounsaturated fatty acids.oleyl-coenzyme A;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oleyl-coenzyme A oleyl-coenzyme A
oleyl-CoA



Copyright© 1995 Williams & Wilkins. All rights reserved.

olfactie olfactie , olfacty (ol-fak´te)
The unit of smell; the threshold of olfactory stimulation, or the point where the smell is just received in the olfactometer.olfacty; [see olfaction]



Copyright© 1995 Williams & Wilkins. All rights reserved.

olfaction olfaction (ol-fak´shun)
1. The sense of smell.smell (2); 2. The act of smelling.osmesis, osphresis; [L. ol- facio, pp. -factus, to smell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

olfactology olfactology (ol´fak-tol´-o-je)
Study of the sense of smell. [olfaction + G. logos, study]



Copyright© 1995 Williams & Wilkins. All rights reserved.

olfactometer olfactometer (ol´fak-tom´e-ter)
A device for estimating the keenness of the sense of smell. [L. olfactus, smell, + G. metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

olfactometry olfactometry (ol´fak-tom´e-tre)
Determination of the degree of sensibility of the olfactory organ.



Copyright© 1995 Williams & Wilkins. All rights reserved.

olfactophobia olfactophobia (ol-fak-to-fo´be-a)
Morbid fear of odors.osmophobia, osphresiophobia; [L. olfactus, smell, + G. phobos, fear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

olfactory olfactory (ol-fak´to-re)
Relating to the sense of smell.osmatic, osphretic; [see olfaction]



Copyright© 1995 Williams & Wilkins. All rights reserved.

olfacty olfacty (ol-fak´te)
olfactie



Copyright© 1995 Williams & Wilkins. All rights reserved.

olibanum olibanum (o-lib´a-num)
A gum resin from several trees of the genus Boswellia (family Burseraceae); has been used as a stimulant expectorant in bronchitis, for fumigations, and as incense.frankincense, thus; [Ar. al, the, + luban, frankincense]



Copyright© 1995 Williams & Wilkins. All rights reserved.

olig- olig-
See oligo-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligamnios oligamnios (ol-i-gam´ne-os)
oligohydramnios



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligemia oligemia (ol-i-ge´me-a)
A deficiency in the amount of blood in the body or any organ or tissue. [oligo- + G. haima, blood]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligemic oligemic (ol-i-ge´mik)
Pertaining to or characterized by oligemia.



Copyright© 1995 Williams & Wilkins. All rights reserved.

olighemia olighemia (ol-ig-he´me-a)
Obsolete term for oligemia.



Copyright© 1995 Williams & Wilkins. All rights reserved.

olighidria olighidria , oligidria (ol-ig-hid´re-a, -id´re-a)
Scanty perspiration. [oligo- + G. hidros, sweat]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligo- oligo- , olig-
1. A few, a little; too little, too few. 2. In chemistry, used in contrast to "poly-" in describing polymers; e.g., oligosaccharide. [G. oligos, few]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligoamnios oligoamnios (ol´i-go-am´ne-os)
oligohydramnios [oligo- + amnion]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligocholia oligocholia (ol´i-go-ko´le-a)
A deficient secretion of bile. [oligo- + G. chole, bile]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligochylia oligochylia (ol´i-go-kI´le-a)
A deficiency of gastric juice. [oligo- + G. chylos, juice]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligochymia oligochymia (ol´i-go-kI´me-a)
A deficiency of chyme. [oligo- + G. chymos, juice]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligocystic oligocystic (ol´i-go-sis´tik)
Consisting of only a few cysts, as occasionally observed in certain examples of hydatidiform mole and other lesions that ordinarily have numerous cysts. [oligo- + G. kystis, bladder, cyst]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligodactyly oligodactyly , oligodactylia (ol´i-go-dak´ti-le, -dak-til´e-a)
Presence of fewer than five digits on one or more limbs. [oligo- + G. daktylos, finger or toe]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligodendria oligodendria (ol´i-go-den´dre-a)
oligodendroglia



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligodendroblast oligodendroblast (ol´i-go-den´dro-blast)
A primitive glial cell that is the normal precursor cell of the oligodendrocyte.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligodendroblastoma oligodendroblastoma (ol´i-go-den´dro-blas-to´ma)
Obsolete term for oligodendroglioma. [oligo- + G. dendron, tree, + blastos, germ, + -oma]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligodendrocyte oligodendrocyte (ol´i-go-den´dro-sIt)
A cell of the oligodendroglia.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligodendroglia oligodendroglia (ol´I-go-den-drog´le-a)
One of the three types of glia cells (the other two being macroglia or astrocytes, and microglia) that, together with nerve cells, compose the tissue of the central nervous system. O. cells are characterized by variable numbers of veillike or sheetlike processes that are wrapped each around individual axons to form the myelin sheath of nerve fibers in the central nervous system (compared with Schwann cells in the peripheral nervous system); forms myelin in the central nervous system; accordingly, they are more numerous in white matter than in gray matter.oligodendria; [oligo- + G. dendron, tree, + glia, glue]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligodendroglioma oligodendroglioma (ol´i-go-den´dro-glI-o´ma)
A relatively rare, relatively slowly growing glioma derived from oligodendrocytes that occurs most frequently in the cerebrum of adult persons; the neoplasm is grossly homogeneous, fairly well circumscribed, moderately firm, and somewhat gritty in consistency with interstitial calcification sufficiently dense so as to be detected by x-ray imaging of the skull. Microscopically, an o. is characterized by numerous, small, round, or ovoid, oligodendroglial cells with small, deeply stained nuclei (rarely observed in mitosis), and palely stained, indistinct cytoplasm; the neoplastic cells are rather uniformly distributed in a sparse, fibrillary stroma with scattered calcific bodies and an often prominent arcuate vasculature. [oligo- + G. dendron, tree, + glia, + -oma]
anaplastic o. an aggressive o. characterized by prominent nuclear pleomorphism, mitoses, and increased cellularity.pleomorphic o;
pleomorphic o. anaplastic o



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligodipsia oligodipsia (ol´i-go-dip´se-a)
Abnormal lack of thirst. See also hypodipsia. [oligo- + G. dipsa, thirst]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligodontia oligodontia (ol´i-go-don´she-a)
hypodontia [oligo- + G. odous, tooth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligodynamic oligodynamic (ol´i-go-dI-nam´ik)
Active in very small quantity; e.g., the germicidal effect of an exceedingly dilute solution (such as one to one hundred million) of copper in distilled water. [oligo- + G. dynamis, power]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligogalactia oligogalactia (ol´i-go-ga-lak´te-a, -she-a)
Slight or scant secretion of milk. [oligo- + G. gala, milk]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligoglucan-branching glycosyltransferase oligoglucan-branching glycosyltransferase (ol´i-go-glu´kan)
1,4-a-d-glucan 6-a-d-glucosyltransferase



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligo-a1,6-glucosidase oligo-a1,6-glucosidase
A glucanohydrolase cleaving a-1,6 links in isomaltose and dextrins produced from starch and glycogen by a-amylase; secreted into the duodenum; a deficiency of this enzyme leads to defects in intestinal digestion of limit dextrins. See also sucrose a-d-glucohydrolase.isomaltase, limit dextrinase (2);



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligohydramnios oligohydramnios (ol´i-go-hI-dram´ne-os)
The presence of an insufficient amount of amniotic fluid (less than 300 ml at term).oligamnios, oligoamnios; [oligo- + G. hydor, water, + amnion]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligohydruria oligohydruria (ol´i-go-hI-dru´re-a)
Obsolete term for excretion of small quantities of urine, as seen in dehydration. [oligo- + G. hydor, water, + ouron, urine]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligolecithal oligolecithal (ol´i-go-les´i-thal)
Having little yolk; denoting an egg in which there is only a little scattered deutoplasm. [oligo- + G. lekithos, yolk]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligomenorrhea oligomenorrhea (ol´i-go-men-o-re´a)
Scanty menstruation. [oligo- + menorrhea]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligomer oligomer (ol´i-go-mer)
A polymer containing only a few repeating units, a "few" generally considered as less than 20.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligomorphic oligomorphic (ol´-i-go-mor´fik)
Presenting few changes of form; not polymorphic. [oligo- + G. morphe, form]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligonephronic oligonephronic (ol´i-go-nef-ron´ik)
Characterized by a reduced number of nephrons.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligonucleotide oligonucleotide (ol´i-go-nu´kle-o-tId)
A compound made up of the condensation of a small number (typically less than twenty) of nucleotides. Cf. polynucleotide.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligopepsia oligopepsia (ol´i-go-pep´se-a)
hypopepsia



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligopeptide oligopeptide (ol´igo-pep-tId)
A peptide whose molecule contains a few amino acid residues up to about 20.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligopeptide 20 oligopeptide 20
A compound made up of the condensation of a small number (typically less than 20) of amino acids. Cf. polypeptide.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligophrenia oligophrenia (ol´i-go-fre´ne-a)
mental retardation
phenylpyruvate oligophrenia phenylketonuria



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligoplastic oligoplastic (ol´i-go-plas´tik)
Deficient in reparative power. [oligo- + G. plasso, to form]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligopnea oligopnea (ol´i-gop-ne´a, -gop´ne-a)
hypopnea [oligo- + G. pnoe, breath]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligoptyalism oligoptyalism (ol´i-go-tI´a-lizm, ol´i-gop-tI´)
A scanty secretion of saliva.oligosialia; [oligo- + G. ptyalon, saliva]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligoria oligoria (ol-i-gor´e-a)
An abnormal indifference toward or dislike of persons or things. [G. oligoria, negligence, slight esteem, fr. oligos, little, + ora, care, regard]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligosaccharide oligosaccharide (ol´i-go-sak´a-rId)
A compound made up of the condensation of a small number of monosaccharide units. Cf. polysaccharide.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligosialia oligosialia (ol´i-go-sI-a´le-a)
oligoptyalism [oligo- + G. sialon, saliva]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligospermia oligospermia , oligospermatism (ol-i-go-sper´me-a, -ma-tizm)
A subnormal concentration of spermatozoa in the penile ejaculate.oligozoospermatism, oligozoospermia; [oligo- + G. sperma, seed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligosymptomatic oligosymptomatic (ol´i-go-simp-to-mat´ik)
Having few or minor symptoms.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligosynaptic oligosynaptic (ol´i-go-si-nap´tik)
Referring to neural conduction pathways that are interrupted by only a few synaptic junctions, i.e., made up of a sequence of only few nerve cells, in contrast to polysynaptic pathways.paucisynaptic;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligothymia oligothymia (ol´i-go-thI´me-a)
Rarely used term for a poverty or loss of affect. [oligo- + -thymia]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligotrichia oligotrichia (ol´i-go-trik´e-a)
hypotrichosis



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligotrichosis oligotrichosis (ol´i-go-tri-ko´sis)
hypotrichosis



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligotrophia oligotrophia , oligotrophy (ol´i-go-tro´fe-a, -got´ro-fe)
Deficient nutrition. [oligo- + G. trophe, nourishment]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oligozoospermatism oligozoospermatism , oligozoospermia (ol´i-go-zo´o-sper´ma-tizm, -sper´me-a)
oligospermia [oligo- + G. zoon, animal, + sperma, seed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oliguresia oliguresia , oliguresis (ol´i-gu-re´se-a, -re´sis)
oliguria [oligo- + G. ouresis, urination]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oliguria oliguria (ol-i-gu´re-a)
Scanty urine production.oliguresia, oliguresis; [oligo- + G. ouron, urine]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oliva oliva,, pl. oli´vae (o-lI´va) [NA]
A smooth oval prominence of the ventrolateral surface of the medulla oblongata lateral to the pyramidal tract, corresponding to the inferior olivary nucleus.corpus olivare, inferior olive, olivary body, olivary eminence, olive (1); [L.]
o. infe´rior the oliva.
o. supe´rior dorsal nucleus of trapezoid body



Copyright© 1995 Williams & Wilkins. All rights reserved.

olivary olivary (ol´i-var-e)
1. Relating to the oliva. 2. Relating to or shaped like an olive.



Copyright© 1995 Williams & Wilkins. All rights reserved.

olive olive (ol´iv)
1. oliva 2. Common name for a tree of the genus Olea (family Oleaceae) or its fruit. [L. oliva]
inferior o. oliva
superior o. dorsal nucleus of trapezoid body



Copyright© 1995 Williams & Wilkins. All rights reserved.

olive oil olive oil
The expressed oil of the fruit of Olea europaea; used as a cholagogue, laxative, and emollient, in the preparation of liniments, and in the preparation of foods.



Copyright© 1995 Williams & Wilkins. All rights reserved.

olivifugal olivifugal (ol´i-vif´yu-gal)
In a direction away from the olive. [oliva + L. fugio, to flee]



Copyright© 1995 Williams & Wilkins. All rights reserved.

olivipetal olivipetal (ol´i-vip´e-tal)
In a direction toward the olive. [oliva + L. peto, to seek]



Copyright© 1995 Williams & Wilkins. All rights reserved.

olivocochlear olivocochlear (ol´i-vo-kok´le-ar)
See olivocochlear bundle.



Copyright© 1995 Williams & Wilkins. All rights reserved.

olivopontocerebellar olivopontocerebellar (ol´i-vo-pon´to-sar-e-bel´ar)
Relating to the olivary nucleus, basis pontis, and cerebellum.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ollendorf Ollendorf
Helene, German dermatologist, fl. 1928. See Buschke-O. syndrome.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ollier Ollier
Louis X.E.L., French surgeon, 1830-1900. See O. graft; O.'s disease, method, theory; O.-Thiersch graft.



Copyright© 1995 Williams & Wilkins. All rights reserved.

-ology -ology
See -logia.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ololiuqui ololiuqui (o-lo-lyu´ke)
A hallucinogen used in ceremonies by the Aztec Indians in Mexico; contains ergot alkaloids and derivatives of lysergic acid. See also Rivea corymbosa, Ipomoea rubrocoerulea var. praecox.



Copyright© 1995 Williams & Wilkins. All rights reserved.

olophonia olophonia (ol´o-fo´ne-a)
Impaired speech due to an anatomical defect in the vocal organs. [G. oloos, destroyed, lost, + phone, voice]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Olszewski Olszewski
Jerzy, Polish-Canadian neuropathologist, 1966. See Steele-Richardson-O. disease, syndrome.



Copyright© 1995 Williams & Wilkins. All rights reserved.

-oma -oma
A tumor or neoplasm (added to words from G. roots). [G. -oma]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omasitis omasitis (o-ma-sI´tis)
Inflammation of the omasum.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omasum omasum (o-ma´sum)
The third stomach division of a ruminant.psalterium (2); [L. bullock's tripe]



Copyright© 1995 Williams & Wilkins. All rights reserved.

-omata -omata
Plural of -oma.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ombrédanne Ombrédanne
Louis, French surgeon, 1871-1956. See O. operation.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ombrophobia ombrophobia (om-bro-fo´be-a)
Morbid fear of rain. [G. ombros, rainstorm, + phobos, fear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Omenn Omenn
Gilbert S., U.S. internist, *1941. See O.'s syndrome.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omental omental (o-men´tal)
Relating to the omentum.epiploic;



Copyright© 1995 Williams & Wilkins. All rights reserved.

omentectomy omentectomy (o-men-tek´to-me)
Resection or excision of the omentum.omentumectomy; [omentum + G. ektome, excision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omentitis omentitis (o-men-tI´tis)
Peritonitis involving the omentum. [L. omentum + G. -itis, inflammation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omento- omento- , oment-
The omentum. See also epiplo-. [L. omentum]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omentofixation omentofixation (o-men´to-fik-sa´shun)
omentopexy



Copyright© 1995 Williams & Wilkins. All rights reserved.

omentopexy omentopexy (o-men´to-pek-se)
1. Suture of the great omentum to the abdominal wall to induce collateral portal circulation. 2. Suture of the omentum to another organ to increase arterial circulation. See also omentoplasty.omentofixation; [omento- + G. pexis, fixation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omentoplasty omentoplasty (o-men´to-plas-te)
Use of the greater omentum to cover or fill a defect, augment arterial or portal venous circulation, absorb effusions, or increase lymphatic drainage. See also omentopexy. [omento- + G. plastos, formed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omentorrhaphy omentorrhaphy (o-men-tor´a-fe)
Suture of an opening in the omentum. [omento- + G. rhaphe, suture]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omentovolvulus omentovolvulus (o-men-to-vol´vyu-lus)
Twisting of the omentum.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omentulum omentulum (o-men´tyu-lum)
lesser omentum [Mod. L. dim. of omentum]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omentum omentum, pl. omenta (o-men´tum, -ta) [NA]
A fold of peritoneum passing from the stomach to another abdominal organ. [L. the membrane that encloses the bowels]
gastrocolic o. greater o
gastrohepatic o. lesser o
gastrosplenic o. gastrosplenic ligament
greater o. a peritoneal fold passing from the greater curvature of the stomach to the transverse colon, hanging like an apron in front of the intestines.o. majus [NA], caul (2), cowl, epiploon, gastrocolic o., pileus, velum (3);
lesser o. a peritoneal fold passing from the margins of the porta hepatis and the bottom of the fissure of the ductus venosus to the lesser curvature of the stomach and to the the upper border of the duodenum for a distance of about 2 cm beyond the gastroduodenal pylorus.o. minus [NA], gastrohepatic o., omentulum;
o. ma´jus [NA] greater o
o. mi´nus [NA] lesser o



Copyright© 1995 Williams & Wilkins. All rights reserved.

omentumectomy omentumectomy (o-men-tu-mek´to-me)
omentectomy



Copyright© 1995 Williams & Wilkins. All rights reserved.

omeprazole omeprazole (o-me´pra-zol)
A drug which blocks the transport of hydrogen ions into the stomach and is used as an antiulcerative, and in treatment of Zollinger-Ellison syndrome.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ommaya Ommaya
Ayub, 20th century U.S. neurosurgeon. See O. reservoir.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omn. hor. omn. hor.
Abbreviation for L. omni hora, every hour.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omnipotence of thought omnipotence of thought (om-nip´o-tens)
A childish or magical thought process whereby instantaneous gratification of fantasies and wishes is believed to be imminent.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omnivorous omnivorous (om-niv´o-rus)
Living on food of all kinds, upon both animal and vegetable food. [L. omnis, all, + voro, to eat]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omo- omo-
The shoulder (sometimes including the upper arm). [G. omos, shoulder]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omoclavicular omoclavicular (o´mo-kla-vik´yu-lar)
Relating to the shoulder and the clavicle; denoting an anomalous muscle attached to the coracoid process or upper edge of the scapula and to the clavicle.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omohyoid omohyoid (o-mo-hI´oyd)
omohyoid muscle



Copyright© 1995 Williams & Wilkins. All rights reserved.

omophagia omophagia (o-mo-fa´je-a)
The eating of raw food, especially of raw flesh. [G. omos, raw, + phago, to eat]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omothyroid omothyroid (o-mo-thI´royd)
Denoting a band of muscular fibers passing between the superior cornu of the thyroid cartilage and the omohyoid muscle.



Copyright© 1995 Williams & Wilkins. All rights reserved.

OMP OMP
Abbreviation for oligo-N-methylmorpholinium propylene oxide; orotidylic acid; orotidylate; orotidine 5´-monophosphate.



Copyright© 1995 Williams & Wilkins. All rights reserved.

OMPA OMPA
Abbreviation for octamethyl pyrophosphoramide.



Copyright© 1995 Williams & Wilkins. All rights reserved.

OMP decarboxylase OMP decarboxylase
orotidylic acid decarboxylase



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphal- omphal- , omphalo-
The umbilicus, the navel. [G. omphalos, navel (umbilicus)]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalectomy omphalectomy (om-fa-lek´to-me)
Excision of the umbilicus or of a neoplasm connected with it. [omphal- + G. ektome, excision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalelcosis omphalelcosis (om´fal-el-ko´sis)
Ulceration at the umbilicus. [omphal- + G. helkosis, ulceration]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalic omphalic (om-fal´ik)
umbilical [G. omphalos, umbilicus]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalitis omphalitis (om-fa-lI´tis)
Inflammation of the umbilicus and surrounding parts.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalo- omphalo-
See omphal-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphaloangiopagus omphaloangiopagus (om´fa-lo-an-je-op´a-gus)
Unequal conjoined twins in which the parasite derives its blood supply from the placenta of the autosite. See conjoined twins, under twin.allantoidoangiopagus; [omphalo- + G. angeion, vessel, + pagos, something fixed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalocele omphalocele (om´fal-o-sel, om´fa-lo-)
Congenital herniation of viscera into the base of the umbilical cord, with a covering membranous sac of peritoneum-amnion. The umbilical cord is inserted into the sac here, in contradistinction to its attachment in gastroschisis. See also umbilical hernia.amniocele, exomphalos (3), exumbilication (3); [omphalo- + G. kele, hernia]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphaloenteric omphaloenteric (om´fa-lo-en-tar-ik)
Relating to the umbilicus and the intestine.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalomesenteric omphalomesenteric (om´fa-lo-mez-en-tar´ik)
1. Term denoting relationship of the midgut to the yolk sac. As the head and tail folds of the embryo continue to form, this relationship is diminished and is represented by a narrow yolk stalk or vitelline duct. 2. Relating to the vitelline duct.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalopagus omphalopagus (om´fa-lop´a-gus)
Conjoined twins united at their umbilical regions. See conjoined twins, under twin.monomphalus; [omphalo- + G. pagos, something fixed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalophlebitis omphalophlebitis (om´fa-lo-fle-bI´tis)
Inflammation of the umbilical veins. [omphalo- + G. phleps, vein, + -itis, inflammation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalorrhagia omphalorrhagia (om´fa-lo-ra´je-a)
Bleeding from the umbilicus. [omphalo- + G. rhegnymi, to burst forth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalorrhea omphalorrhea (om´fa-lo-re´a)
A serous discharge from the umbilicus. [omphalo- + G. rhoia, flow]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalorrhexis omphalorrhexis (om´fa-lo-rek´sis)
Rupture of the umbilical cord during childbirth. [omphalo- + G. rhexis, rupture]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalos omphalos (om´fa-los)
Rarely used term for umbilicus. [G. navel]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalosite omphalosite (om´fa-lo-sIt)
Underdeveloped twin of allantoidangiopagous twin; joined by umbilical vessels.placental parasitic twin; [omphalo- + G. sitos, food]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalospinous omphalospinous (om´fa-lo-spI´nus)
Denoting a line connecting the umbilicus and the anterior superior spine of the ilium, on which lies McBurney's point.



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalotomy omphalotomy (om-fa-lot´o-me)
Cutting of the umbilical cord at birth. [omphalo- + G. tome, incision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalotripsy omphalotripsy (om´fa-lo-trip´se)
Crushing, instead of cutting, the umbilical cord after childbirth. [omphalo- + G. tripsis, a rubbing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalovesical omphalovesical (om´fa-lo-ves´i-kal)
vesicoumbilical



Copyright© 1995 Williams & Wilkins. All rights reserved.

omphalus omphalus (om´fa-lus)
Rarely used term for umbilicus. [G. omphalos, navel]



Copyright© 1995 Williams & Wilkins. All rights reserved.

OMP pyrophosphorylase OMP pyrophosphorylase
orotate phosphoribosyltransferase



Copyright© 1995 Williams & Wilkins. All rights reserved.

OMS OMS
Abbreviation for organic mental syndrome.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onanism onanism (o´nan-izm)
1. The act of a male to spill his seed on the ground; withdrawal of the penis before ejaculation, in order to prevent insemination and fecundation of the ovum. 2. Incorrectly used as a synonym of masturbation. [Onan, son of Judah, who practiced it. Genesis 38:9]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncho- oncho-
See onco-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Onchocerca Onchocerca (ong-ko-ser´ka)
A genus of elongated filariform nematodes (family Onchocercidae) that inhabit the connective tissue of their hosts, usually within firm nodules in which these parasites are coiled and entangled.Oncocerca; [G. onkos, a barb, + kerkos, tail]
O. cervica´lis a species common in the ligamentum nuchae of horses, mules, and asses, where it has been suspected of playing a role in fistulous withers and poll evil.
O. gibso´ni a species that infects the subcutaneous tissues of cattle, buffalo, and sheep.
O. liena´lis a species that inhabits the connective tissue around the ligamentum nuchae, tibiofemoral ligament, spleen capsule, and other sites in cattle and buffalo; although widely distributed, it is not common in the U.S.
O. vol´vulus the blinding nodular worm, a species that causes onchocerciasis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onchocerciasis onchocerciasis (ong´ko-ser-kI´a-sis)
Infection with Onchocerca (especially O. volvulus, a filarial nematode transmitted from person to person by black flies of the genus Simulium), marked by nodular swellings forming a fibrous cyst enveloping the coiled parasites; microfilariae move freely out of the nodule and escape into the intercellular lymph in the dermis. Dermatological changes often develop, especially in Africa, resulting in intense pruritus, scaly or lichenoid skin, depigmentation, and destruction of elastic fibers. Most important are the ocular complications that may develop after a long chronic course, with blindness frequently occurring in advanced cases, due to the presence of living or dead microfilariae seen by slit lamp biomicroscopy.blinding disease, onchocercosis, volvulosis;
ocular o. ocular complications, such as keratitis, iridocyclitis, or retrobulbar neuritis, caused by the microfilariae of Onchocerca volvulus.river blindness;



Copyright© 1995 Williams & Wilkins. All rights reserved.

onchocercid onchocercid (ong-ko-ser´kid)
Common name for members of the family Onchocercidae.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Onchocercidae Onchocercidae (ong-ko-ser´ki-de)
A family of nematode parasites (superfamily Filarioidea) characterized by production of microfilariae; it includes the genera Onchocerca, Wuchereria, Brugia, Loa, and Mansonella.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onchocercosis onchocercosis (ong´ko-ser-ko´sis)
onchocerciasis



Copyright© 1995 Williams & Wilkins. All rights reserved.

onco- onco- , oncho-
A tumor. [G. onkos, bulk, mass]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oncocerca Oncocerca (ong-ko-ser´ka)
Onchocerca



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncocyte oncocyte (ong´ko-sIt)
A large, granular, acidophilic tumor cell containing numerous mitochondria; a neoplastic oxyphil cell. [onco- + G. kytos, cell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncocytoma oncocytoma (ong´ko-sI-to´ma)
A glandular tumor composed of large cells with cytoplasm that is granular and eosinophilic due to the presence of abundant mitochondria; occurs uncommonly in the kidney, salivary glands, and endocrine glands.oxyphil adenoma; [onco- + G. kytos, cell, + -oma, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncofetal oncofetal (ong-ko-fe´tal)
Relating to tumor-associated substances present in fetal tissue, as o. antigens.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncogene oncogene (ong´ko-jen)
1. Any of a family of genes which under normal circumstances code for proteins involved in cell growth or regulation (e.g., protein kinases, GTPases, nuclear proteins, growth factors) but may foster malignant processes if mutated or activated by contact with retroviruses. Identified oncogenes include the ras, originally associated with bladder tumors, and the p53, a mutated version of a gene on chromosome 17 which normally corrects for mutations caused by ultraviolet radiation. p53 now has been shown to be involved in cancers of the breast, cervix, ovary, and lung, among others. Oncogenes often work in concert to produce cancer, and their action may be exacerbated by retroviruses, jumping genes, or inherited genetic mutations. See antioncogene. 2. Found in certain DNA tumor viruses. It is required for viral replication.transforming gene; [onco- + gene]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncogenesis oncogenesis (ong-ko-jen´e-sis)
Origin and growth of a neoplasm. [onco- + G. genesis, production]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncogenic oncogenic (ong-ko-jen´ik)
oncogenous



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncogenous oncogenous (ong-koj´e-nus)
Causing, inducing, or being suitable for the formation and development of a neoplasm.oncogenic;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncograph oncograph (ong´ko-graf)
A recording oncometer, or the recording portion of an oncometer. [onco- + G. graphe, a record]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncography oncography (ong´kog´ra-fe)
Graphic representation, by means of a special apparatus, of the size and configuration of an organ.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncoides oncoides (ong-koy´dez)
Intumescence or turgescence. [onco- + G. eidos, resemblance]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncologist oncologist (ong-kol´o-jist)
A specialist in oncology.
radiation o. radiotherapist



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncology oncology (ong-kol´o-je)
The study or science dealing with the physical, chemical, and biologic properties and features of neoplasms, including causation, pathogenesis, and treatment. [onco- + G. logos, study]
radiation o. the medical specialty of radiation therapy; the study of radiation treatment of neoplasms.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncolysis oncolysis (ong-kol´i-sis)
Destruction of a neoplasm; sometimes used with reference to the reduction of any swelling or mass. [onco- + G. lysis, dissolution]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncolytic oncolytic (ong-ko-lit´ik)
Pertaining to, characterized by, or causing oncolysis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oncomelania Oncomelania (ong´ko-me-la´nI-a)
A medically important genus of amphibious freshwater operculate snails of the family Hydrobiidae (subfamily Hydrobiinae; subclass Prosobranchiata). In the Orient, several subspecies of O. hupensis serve as intermediate hosts of the oriental blood fluke, Schistosoma japonicum. [onco- + G. melas (melan-), black]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncometer oncometer (ong-kom´e-ter)
1. An instrument for measuring the size and configuration of the kidneys and other organs. 2. The measuring, as distinguished from the recording part of the oncograph. [onco- + G. metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncometric oncometric (ong-ko-met´rik)
Relating to oncometry.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncometry oncometry (ong-kom´e-tre)
Measurement of the size of an organ.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncornaviruses oncornaviruses (ong-kor´na-vI´rus-ez)
Oncovirinae



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncosis oncosis (ong-ko´sis)
A condition characterized by the formation of one or more neoplasms or tumors. [G. onkosis, swelling, fr. onkos, bulk, mass]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncosphere oncosphere (ong´-ko-sfer)
hexacanth [onco- + G. sphaira, sphere]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncotherapy oncotherapy (ong-ko-thar´a-pe)
Treatment of tumors.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncotic oncotic (ong-kot´ik)
Relating to or caused by edema or any swelling (oncosis).



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncotomy oncotomy (ong-kot´o-me)
Rarely used term for incision of an abscess, cyst, or other tumor. [onco- + G. tome, incision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncotropic oncotropic (ong´ko-trop´ik)
Manifesting a special affinity for neoplasms or neoplastic cells.tumoraffin; [onco- + G. trope, a turning]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oncovirinae Oncovirinae (ong-ko-vir´i-ne)
A subfamily of viruses (family Retroviridae) composed of the RNA tumor viruses that contain two identical plus stranded RNA molecules. Subgroups are based on antigenicity, host range, and kind of malignancy induced (avian, feline, hamster, or murine leukemia-sarcoma complex; murine mammary tumor virus; primate oncoviruses). Like other retroviruses, the oncoviruses contain RNA-dependent DNA polymerases (reverse transcriptases). Virions, on the basis of morphology and antigenicity, are of four types: 1) type A, found only within infected cells and seemingly immature in that there is no electron-dense nucleoid; 2) type B, having an eccentric electron-dense nucleoid and associated with the Bittner mammary tumor; 3) type C, having a centrally located, electron-dense nucleoid and associated with leukemia-sarcoma complexes of various species; 4) type D, having a central electron-dense nucleoid but differing in other respects from type C. An important aspect of these viruses seems to be utilization of viral reverse transcriptase to make DNA which can be integrated into the DNA of the host cell and will replicate along with cellular DNA.oncornaviruses;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oncovirus oncovirus (ong´ko-vI´rus)
Any virus of the subfamily Oncovirinae. See also oncogenic virus.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ondansetron ondansetron (on-dan´se-tron)
A serotonin 5-HT3 receptor antagonist used as an antiemetic, particularly in patients undergoing chemotherapy or radiation treatment for cancer.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ondine Ondine
German mythological character.



Copyright© 1995 Williams & Wilkins. All rights reserved.

-one -one
Suffix indicating a ketone (-CO-) group.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oneiric oneiric (o-nI´rik)
1. Pertaining to dreams. 2. Pertaining to the clinical state of oneirophrenia.oniric; [G. oneiros, dream]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oneirism oneirism (o-nI´rizm)
A waking dream state. [G. oneiros, dream]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oneirocritical oneirocritical (o-nI-ro-krit´i-kal)
Rarely used term pertaining to the logic of dreams. [G. oneiros, dream, + kritikos, skilled in judgment]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oneirodynia oneirodynia (o-nI-ro-din´e-a)
Rarely used term for an unpleasant or painful dream. [G. oneiros, dream, + odyne, pain]
o. acti´va somnambulism (1)
o. gra´vis nightmare



Copyright© 1995 Williams & Wilkins. All rights reserved.

oneirogmus oneirogmus (o´nI-rog´mus)
Nocturnal emission of semen, often related to erotic dreams. See also wet dream. [G. oneirogmos, an effusion of semen during sleep]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oneirology oneirology (o-nI-rol´o-je)
The study of dreams and their content. [G. oneiros, dream, + logos, study]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oneirophrenia oneirophrenia (o-nI-ro-fre´ne-a)
A state in which hallucinations occur, caused by such conditions as prolonged deprivation of sleep, sensory isolation, and a variety of drugs. [G. oneiros, dream, + phren, mind]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oneiroscopy oneiroscopy (o-nI-ros´ko-pe)
Rarely used term for the diagnosis of a person's mental state by an analysis of his dreams. [G. oneiros, dream, + skopeo, to examine]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oniomania oniomania (o´ne-o-ma´ne-a)
Rarely used term for the morbidly exaggerated need or urge to buy beyond the realistic needs of the individual. [G. onios, for sale, + mania, insanity]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oniric oniric (o-nI´rik)
oneiric



Copyright© 1995 Williams & Wilkins. All rights reserved.

-onium -onium
Suffix indicating a positively charged radical; e.g., ammonium, NH4+.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onko- onko-
See onco-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onlay onlay (on´la)
1. A metal (usually gold) cast restoration of the occlusal surface of a posterior tooth or the lingual surface of an anterior tooth, the entire surface of which is in dentin without side walls; retention in the anterior tooth is by pins and in the posterior by pins and/or boxes in retentive grooves in the buccal and lingual walls. 2. A graft applied on the exterior of a bone.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Onodi Onodi
A., 20th century Hungarian laryngologist. See Onodi cell.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onomatomania onomatomania (on´o-mat-o-ma´ne-a)
An abnormal impulse to dwell upon certain words and their supposed significance, or to frantically try to recall a particular word. [G. onoma, name, + mania, frenzy]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onomatophobia onomatophobia (on´o-mat-o-fo´be-a)
Abnormal dread of certain words or names because of their supposed significance.nomatophobia; [G. onoma, name, + phobos, fear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onomatopoiesis onomatopoiesis (on´o-mat´o-poy-e´sis)
The making of a name or word, especially to express or imitate a natural sound (e.g., hiss, crash, boom); in psychiatry, the tendency to make new words of this type is said to characterize some persons with schizophrenia. See also neologism. [G. onoma, name, + poiesis, making]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ontogenesis ontogenesis (on-to-jen´e-sis)
ontogeny



Copyright© 1995 Williams & Wilkins. All rights reserved.

ontogenetic ontogenetic , ontogenic (on´to-je-net´ik, -jen´ik)
Relating to ontogeny.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ontogeny ontogeny (on-toj´e-ne)
Development of the individual, as distinguished from phylogeny, which is evolutionary development of the species.ontogenesis; [G. on, being, + genesis, origin]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ontology ontology (on-tol´o-je)
A traditional branch of metaphysics that deals with problems of being, existence, inner nature, meaning, etc. It is fundamental to problems involving normality and disease, individuality, responsibility, and the analysis of values. In recent years, it has been slowly assuming a place as a branch of medicine proper.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Onufrowicz Onufrowicz (on-u-fro´-wikz)
Wladislaus, Swiss anatomist, 1836-1900. See Onuf's nucleus.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onyalai onyalai (on-i-al´a)
An acute disease affecting natives of Central Africa, characterized by bloody vesicles of the mouth and other mucous surfaces, hematuria, and melena; defective nutrition may be the cause.akembe, kafindo;



Copyright© 1995 Williams & Wilkins. All rights reserved.

onych- onych-
See onycho-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychalgia onychalgia (on-i-kal´je-a)
Pain in the nails. [onycho- + G. algos, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychatrophia onychatrophia , onychatrophy (on´i-ka-tro´fe-a, on-ik-at´ro-fe)
Atrophy of the nails. [onycho- + G. atrophia, atrophy]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychauxis onychauxis (on-i-kawk´sis)
Marked overgrowth of the fingernails or toenails. [onycho- + G. auxe, increase]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychectomy onychectomy (on-i-kek´to-me)
Ablation of a toenail or fingernail. [onycho- + G. ektome, excision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychia onychia (o-nik´e-a)
Inflammation of the matrix of the nail.onychitis, onyxitis; [onycho- + G. -ia, condition]
o. latera´lis paronychia
o. malig´na acute o. occurring spontaneously in debilitated patients, or in response to slight trauma.Wardrop's disease;
o. periungua´lis paronychia
o. sic´ca a condition characterized by brittle nails.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychitis onychitis (on-i-kI´tis)
onychia



Copyright© 1995 Williams & Wilkins. All rights reserved.

onycho- onycho- , onych-
A finger nail, a toenail. [G. onyx, nail]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychoclasis onychoclasis (on-i-kok´la-sis)
Breaking of the nails. [onycho- + G. klasis, breaking]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychocryptosis onychocryptosis (on´i-ko-krip-to´sis)
ingrown nail [onycho- + G. krypto, to conceal]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychodystrophy onychodystrophy (on´i-ko-dis´tro-fe)
Dystrophic changes in the nails occurring as a congenital defect or due to any illness or injury that may cause a malformed nail. [onycho- + G. dys-, bad, + trophe, nourishment]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychograph onychograph (on´i-ko-graf)
An instrument for recording the capillary blood pressure as shown by the circulation under the nail. [onycho- + G. grapho, to write]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychogryphosis onychogryphosis (on´i-ko-gri-fo´sis)
onychogryposis



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychogryposis onychogryposis (on´i-ko-gri-po´sis)
Enlargement with increased thickening and curvature of the fingernails or toenails.gryposis unguium, onychogryphosis; [onycho- + G. gryposis, a curvature]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychoheterotopia onychoheterotopia (on´i-ko-het-er-o-to´pe-a)
Abnormal placement of nails.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychoid onychoid (on´i-koyd)
Resembling a fingernail in structure or form. [onycho- + G. eidos, resemblance]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychology onychology (on-i-kol´o-je)
Study of the nails. [onycho- + G. logos, treatise]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onycholysis onycholysis (on-i-kol´i-sis)
Loosening of the nails, beginning at the free border, and usually incomplete. [onycho- + G. lysis, loosening]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychoma onychoma (on-i-ko´ma)
A tumor arising from the nail bed. [onycho- + G. -oma, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychomadesis onychomadesis (on´i-ko-ma-de´sis)
Complete shedding of the nails, usually associated with systemic disease. [onycho- + G. madesis, a growing bald, fr. madao, to be moist, (of hair) fall off]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychomalacia onychomalacia (on´i-ko-ma-la´she-a)
Abnormal softness of the nails. [onycho- + G. malakia, softness]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychomycosis onychomycosis (on´i-ko-mI-ko´sis)
Very common fungus infections of the nails, causing thickening, roughness, and splitting, often caused by Trichophyton rubrum or T. mentagrophytes, Candida in the immunodeficient, and molds in the elderly.ringworm of nails; [onycho- + G. mykes, fungus, + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychonosus onychonosus (on-i-kon´o-sus)
onychopathy [onycho- + G. nosos, disease]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onycho-osteodysplasia onycho-osteodysplasia (on´i-ko-os´te-o-dis-pla´ze-a)
Obsolete term for the nail-patella syndrome.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychopathic onychopathic (on´i-ko-path´ik)
Relating to or suffering from any disease of the nails.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychopathology onychopathology (on´i-ko-pa-thol´o-je)
Study of diseases of the nails.



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychopathy onychopathy (on-i-kop´a-the)
Any disease of the nails.onychonosus, onychosis; [onycho- + G. pathos, suffering]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychophagy onychophagy , onychophagia (on-i-kof´a-je, on´i-ko-fa´je-a)
Habitual nailbiting. [onycho- + G. phago, to eat]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychophosis onychophosis (on´i-ko-fo´sis)
A growth of horny epithelium in the nail bed. [onycho- + G. phos, light, + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychophyma onychophyma (on´i-ko-fI´ma)
Swelling or hypertrophy of the nails. [onycho- + G. phyma, growth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychoplasty onychoplasty (on´i-ko-plas-te)
A corrective or plastic operation on the nail matrix. [onycho- + G. plastos, formed, shaped]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychoptosis onychoptosis (on´i-kop-to´sis)
Falling off of the nails. [onycho- + G. ptosis, a falling]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychorrhexis onychorrhexis (on´i-ko-rek´sis)
Abnormal brittleness of the nails with splitting of the free edge. [onycho- + G. rhexis, a breaking]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychoschizia onychoschizia (on´i-ko-skiz´e-a)
Splitting of the nails in layers. [onycho- + G. schizo, to divide, + -ia, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychosis onychosis (on-i-ko´sis)
onychopathy



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychostroma onychostroma (on´i-ko-stro´ma)
nail bed [onycho- + G. stroma, bedding]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychotillomania onychotillomania (on´i-kot´i-lo-ma´ne-a)
A tendency to pick at the nails. [onycho- + G. tillo, to pluck, + mania, insanity]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychotomy onychotomy (on-i-kot´o-me)
Incision into a toenail or fingernail. [onycho- + G. tome, cutting]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onychotrophy onychotrophy (on-i-kot´ro-fe)
Nutrition of the nails. [onycho- + G. trophe, nourishment]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onyx onyx (on´iks)
nail [G. nail]



Copyright© 1995 Williams & Wilkins. All rights reserved.

onyxis onyxis (on-iks´is)
ingrown nail



Copyright© 1995 Williams & Wilkins. All rights reserved.

onyxitis onyxitis (on-iks-I´tis)
onychia



Copyright© 1995 Williams & Wilkins. All rights reserved.

oo- oo-
Egg, ovary. See also oophor-, ovario-, ovi-, ovo-. [G. oon, egg. OO-]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oocyesis oocyesis (o-o-sI-e´sis)
ovarian pregnancy [G. oon, egg, + kyesis, pregnancy]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oocyst oocyst (o´o-sist)
The encysted form of the fertilized macrogamete, or zygote, in coccidian Sporozoea in which sporogonic multiplication occurs; results in the formation of sporozoites, infectious agents for the next stage of the sporozoan life cycle. [G. oon, egg, + kystis, bladder]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oocyte oocyte (o´o-sIt)
The immature ovum.ovocyte; [G. oon, egg, + kytos, a hollow (cell)]
primary o. an o. during its growth phase and before it completes the first maturation division.
secondary o. an o. in which the first meiotic division is completed; the second meiotic division usually stops short of completion unless fertilization occurs.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oogenesis oogenesis (o-o-jen´e-sis)
Process of formation and development of the ovum.ovigenesis, ovogenesis; [G. oon, egg, + genesis, origin]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oogenetic oogenetic (o-o-je-net´ik)
Producing ova.oogenic, oogenous, ovigenetic, ovigenic, ovigenous;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oogenic oogenic , oogenous (o-o-jen´ik, o-oj´e-nus)
oogenetic



Copyright© 1995 Williams & Wilkins. All rights reserved.

oogonium oogonium, pl. oogonia (o-o-go´ne-um, -a)
1. Primitive germ cells; proliferate by mitotic division. All oogonia develop into primary oocytes prior to birth; no oogonia are present after birth. 2. In fungi, the female gametangium bearing one or more oospores. [G. oon, egg, + gone, generation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ookinesis ookinesis , ookinesia (o´o-ki-ne´sis, -ze-a)
Chromosomal movements of the egg during maturation and fertilization. [G. oon, egg, + kinesis, movement]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ookinete ookinete (o´o-ki-ne´t, -kI´ne´t)
The motile zygote of the malarial organism that penetrates the mosquito stomach to form an oocyst under the outer gut lining; the contents of the oocyst subsequently divide to produce numerous sporozoites.vermicule (2); [G. oon, egg, + kinetos, motile]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oolemma oolemma (o-o-lem´a)
Plasma membrane of the oocyte. [G. oon, egg, + lemma, sheath]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oomycosis oomycosis (o´o-mI-ko´sis)
A mycosis caused by fungi belonging to the class Oomycetes; e.g., rhinosporidiosis, pythiosis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophagia oophagia , oophagy (o-o-fa´je-a, o-of´a-je)
The habitual eating of eggs; subsisting largely on eggs. [G. oon, egg, + phago, to eat]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophor- oophor- , oophoro-
The ovary. See also oo-, ovario-. [Mod. L. oophoron, ovary, fr. G. oophoros, egg-bearing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophoralgia oophoralgia (o-of-or-al´je-a)
ovarialgia [oophor- + G. algos, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophorectomy oophorectomy (o-of-or-ek´to-me)
ovariectomy [G. oon, egg, + phoros, bearing, + ektome, excision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophoritis oophoritis (o-of-or-I´tis)
Inflammation of an ovary.ovaritis; [G. oon, egg, + phoros, a bearing, + -itis, inflammation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophoro- oophoro-
See oophor-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophorocystectomy oophorocystectomy (o-of´or-o-sis-tek´to-me)
Excision of an ovarian cyst.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophorocystosis oophorocystosis (o-of´or-o-sis-to´sis)
Ovarian cyst formation.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophorohysterectomy oophorohysterectomy (o-of´or-o-his-ter-ek´to-me)
ovariohysterectomy



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophoroma oophoroma (o-of-or-o´ma)
An ovarian tumor.ovarioncus;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophoron oophoron (o-of´or-on)
Rarely used term for ovary. [G. oon, egg, + phoros, bearing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophoropathy oophoropathy (o-of-or-op´a-the)
ovariopathy



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophoropeliopexy oophoropeliopexy (o-of´or-o-pel´i-o-pek-se)
oophororrhaphy [oophoro- + G. pellis, pelvis, + pexis, fixation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophoropexy oophoropexy (o-of´or-o-pek-se)
Surgical fixation or suspension of an ovary. [oophoro- + G. pexis, fixation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophoroplasty oophoroplasty (o-of´or-o-plas-te)
Plastic operation upon an ovary. [oophoro- + G. plastos, formed, shaped]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophororrhaphy oophororrhaphy (o-of-o-ror´a-fe)
Suspension of the ovary by attachment to pelvic the wall.oophoropeliopexy; [oophoro- + G. rhaphe, suture]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophorosalpingectomy oophorosalpingectomy (o-of´or-o-sal-pin-jek´to-me)
ovariosalpingectomy



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophorosalpingitis oophorosalpingitis (o-of´or-o-sal-pin-jI´tis)
ovariosalpingitis [oophoro- + salpingitis]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophorostomy oophorostomy (o-of-or-os´to-me)
ovariostomy [oophoro- + G. stoma, mouth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophorotomy oophorotomy (o-of-or-ot´o-me)
ovariotomy [oophoro- + G. tome, incision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oophorrhagia oophorrhagia (o-of-or-ra´je-a)
Ovarian hemorrhage. [oophoro- + G. rhegnymi, to burst forth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ooplasm ooplasm (o´o-plazm)
Protoplasmic portion of the ovum. [G. oon, egg, + plasma, a thing formed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oosome oosome (o´o-som)
A cytoplasmic body in the ovum that passes into the germ cell. [G. oon, egg + soma, body]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oosporangium oosporangium (o´o-spo-ran´je-um)
Obsolete term for oogonium (2) . [oospore + G. angeion, vessel]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oospore oospore (o´o-spor)
A thick-walled fungus spore which develops from a female gamete either through fertilization or parthenogenesis in an oogonium. [see Oospora]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ootheca ootheca (o-oth-e´ka)
1. An egg case found in some lower animals. 2. Rarely used term for ovary. [G. oon, egg, + theke, box, case]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ootid ootid (o´o-tid)
The nearly mature ovum after the first meiotic division has been completed and the second initiated; in most higher mammals, the second meiotic division is not completed unless fertilization occurs. [G. ootidion, a diminutive egg. See -id (2)]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ootype ootype (o´o-tIp)
The central portion of the ovarian complex of trematodes and cestodes in which fertilization takes place and the vitellarian or eggshell materials are coated over the egg; this occurs in a rapid, stamping-mill sequence, after which eggs pass into the uterus for tanning of the shell, storage, and passage toward the genital pore. [G. oon, egg, + typos, stamp, print]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opacification opacification (o-pas´i-fi-ka´shun)
1. The process of making opaque. 2. The formation of opacities. [L. opacus, shady]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opacity opacity (o-pas´i-te)
1. A lack of transparency; an opaque or nontransparent area. 2. On a radiograph, a more transparent area is interpreted as an o. to x-rays in the body. 3. Mental dullness. [L. opacitas, shadiness]
nodular o. a solitary, round, circumscribed shadow found in the lung on chest radiograph; causes include granuloma, primary or metastatic carcinoma, benign tumor, vascular malformation.coin lesion of lungs;
snowball o. a spherical, white body seen in the vitreous in asteroid hyalosis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opalescent opalescent (o-pa-les´ent)
Resembling an opal in the display of various colors; denoting certain bacterial cultures. [Fr. fr. L. opalus, opal]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Opalski Opalski
Adam, Polish physician, 1897-1963. See O. cell.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opaque opaque (o-pak´)
Impervious to light; not translucent or only slightly so. Cf. radiopaque. [Fr. fr. L. opacus, shady]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opeidoscope opeidoscope (op-I´do-skop)
An apparatus for study of voice vibrations by which the vibrations of a diaphragm, started by the voice, move a mirror by which a ray of light is reflected on a screen. [G. ops (op-), a voice, + eidos, appearance, + skopeo, to view]



Copyright© 1995 Williams & Wilkins. All rights reserved.

open open (o´pen)
1. Not closed; exposed, said of a wound. 2. To enter or expose, as a wound or cavity. [A.S.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opening opening (o´pen-ing)
aperture See also aperture, fossa, ostium, orifice.
access o. access
aortic o. aortic hiatus
cardiac o. cardiac orifice
o. to cerebral aqueduct anus cerebri
esophageal o. esophageal hiatus
o. of external acoustic meatus the orifice of the external acoustic meatus in the tympanic portion of the temporal bone.porus acusticus externus [NA], external acoustic foramen, external acoustic pore, external auditory pore, external auditory foramen, orifice of external acoustic meatus;
external o. of urethra external urethral orifice
femoral o. adductor hiatus
ileocecal o. ileocecal orifice
o. of inferior vena cava the orifice through which the inferior vena cava opens into the right atrium.ostium venae cavae inferioris [NA], orifice of inferior vena cava;
o. of internal acoustic meatus the inner opening of the internal acoustic meatus on the posterior surface of the petrous part of the temporal bone.porus acusticus internus [NA], internal acoustic foramen, internal acoustic pore, auditory pore, internal auditory foramen, orifice of internal acoustic meatus;
internal urethral o. internal urethral orifice
lacrimal o. lacrimal punctum
orbital o. the somewhat quadrangular anterior entrance to the orbit which forms the base of the pyramid-shaped orbital cavity. It is bounded by the sharp supra-, infra-, and lateral orbital margins and a less obvious medial margin on each side of the upper nose.aditus orbitae [NA], aperture of orbit;
pharyngeal o. of auditory tube an opening in the upper part of the nasopharynx about 1.2 cm behind the posterior extremity of the inferior concha on each side.ostium pharyngeum tubae auditivae [NA], pharyngeal o. of eustachian tube;
pharyngeal o. of eustachian tube pharyngeal o. of auditory tube
piriform o. anterior nasal aperture
o. of pulmonary trunk the o. of the pulmonary trunk from the right ventricle, guarded by the pulmonary valve.ostium trunci pulmonalis [NA], pulmonary orifice;
o.'s of pulmonary veins the orifices of the pulmonary veins, usually two on each side, in the wall of the left atrium.ostia venarum pulmonalium [NA];
saphenous o. the opening in the fascia lata inferior to the medial part of the inguinal ligament through which the saphenous vein passes to enter the femoral vein.hiatus saphenus [NA], fossa ovalis (2), saphenous hiatus;
o. of the sphenoidal sinus one of the pair of openings in the body of the sphenoid bone through which the sphenoid sinuses communicate with the sphenoethmoidal recess of the nasal cavity.apertura sinus sphenoidalis [NA], sphenoidal sinus aperture;
o. of superior vena cava the point of entry of the superior vena cava into the right atrium.ostium venae cavae superioris [NA], orifice of superior vena cava;
tendinous o. adductor hiatus
tympanic o. of auditory tube an opening in the anterior part of the tympanic cavity below the canal for the tensor tympani muscle.ostium tympanicum tubae auditivae [NA], tympanic o. of eustachian tube;
tympanic o. of canaliculi for chorda tympani the small canal opening found lateral to the pyramidal eminence in the posterior wall of the middle ear cavity from which the chorda tympani nerve emerges to pass anteriorly between the ossicles accompanied by a branch of the stylomastoid artery.apertura tympanica canaliculi chordae tympani [NA];
tympanic o. of eustachian tube tympanic o. of auditory tube
ureteral o. ureteric orifice
urethral o.'s See external urethral orifice, internal urethral orifice.
uterine o. of uterine tubes uterine ostium of uterine tubes
o. of uterus external os of uterus
vaginal o. vaginal orifice
vertical o. vertical dimension



Copyright© 1995 Williams & Wilkins. All rights reserved.

operable operable (op´er-a-bl)
Denoting a patient or condition on which a surgical procedure can be performed with a reasonable expectation of cure or relief.



Copyright© 1995 Williams & Wilkins. All rights reserved.

operant operant (op´er-ant)
In conditioning, any behavior or specific response chosen by the experimenter; its frequency is intended to increase or decrease by the judicious pairing with it of a reinforcer when it occurs.target behavior (1), target response;



Copyright© 1995 Williams & Wilkins. All rights reserved.

operate operate (op´er-at)
1. To work upon the body by the hands or by means of cutting or other instruments to correct a surgical problem. 2. To cause a movement of the bowels; said of a laxative or cathartic remedy. [L. operor, pp. -atus, to work, fr. opus, work]



Copyright© 1995 Williams & Wilkins. All rights reserved.

operation operation (op-er-a´shun)
1. Any surgical procedure. 2. The act, manner, or process of functioning. See also method, procedure, technique.
Abbe o. use of an Abbe flap in plastic surgery of the lips.
Arie-Pitanguy o. a procedure to reduce a large breast by a lozenge-shaped resection of tissue from its inferior pole.Arie-Pitanguy mammaplasty;
Arlt's o. transplantation of the eyelashes back from the edge of the lid in trichiasis.
arterial switch o. o. for complete transposition of the great arteries; the most common way to repair this defect consists of switching the aorta and pulmonary arteries and implanting the coronary arteries into the neoaorta (the original pulmonary artery).
Baldy's o. an obsolete o. for retrodisplacement of the uterus, consisting of bringing the round ligaments through the perforated broad ligaments and attaching them to each other and to the back of the uterus.Webster's o;
Ball's o. division of the sensory nerve trunks supplying the anus, for relief of pruritus ani.
Barkan's o. goniotomy for congenital glaucoma under direct observation of the anterior chamber angle.
Bassini's o. an o. for an inguinal hernia repair; after reduction of the hernia, the sac is twisted, ligated, and cut off, then a new inguinal canal is made by uniting the edge of the internal oblique muscle to the inguinal ligament, placing on this the cord, and covering the latter by the external oblique muscle.
Baudelocque's o. an incision through the posterior cul-de-sac of the vagina for the removal of the ovum, in extrauterine pregnancy.
Belsey Mark IV o. a transthoracic anti-reflux procedure; it restores a 3 to 4 cm length of intraabdominal esophagus, maintains a narrow diameter of the distal esophagus by a gastric fundoplication.
Billroth's o. I excision of the pylorus with end-to-end anastomosis of stomach and duodenum.Billroth I anastomosis;
Billroth's o. II resection of the pylorus with the greater part of the lesser curvature of the stomach, closure of the cut ends of the duodenum and stomach, followed by a gastrojejunostomy.Billroth II anastomosis;
Blalock-Hanlon o. the creation of a large atrial septal defect as a palliative procedure for complete transposition of the great arteries.
Blalock-Taussig o. an o. for congenital malformations of the heart, in which an abnormally small volume of blood passes through the pulmonary circuit; blood from the systemic circulation is directed to the lungs by anastomosing the right or left subclavian artery to the right or left pulmonary artery.
bloodless o. an o. performed with negligible loss of blood.
Bozeman's o. an o. for uterovaginal fistula, the cervix uteri being attached to the bladder and opening into its cavity.
Bricker o. an o. utilizing an isolated segment of ileum to collect urine from the ureters and conduct it to the skin surface.
Brock o. transventricular valvotomy for relief of pulmonic valvar stenosis. Obsolete procedure.
Brunschwig's o. total pelvic exenteration
Burow's o. an o. in which triangles of skin adjacent to a sliding flap are excised to facilitate movement of the flap.
Caldwell-Luc o. an intraoral procedure for opening into the maxillary antrum through the supradental (canine) fossa above the maxillary premolar teeth.intraoral antrostomy, Luc's o;
capital o. obsolete term for an o. of such magnitude or involving vital organs to such an extent that it is per se dangerous to life.
Carmody-Batson o. reduction of fractures of the zygoma and zygomatic arch through an intraoral incision above the maxillary molar teeth.
Caslick's o. an o. for the correction of faulty conformation of the vulva of the mare, a frequent cause of low-grade vaginitis and infertility; consists of surgical closure of the dorsal portion of the vulva.
cesarean o. See cesarean section, cesarean hysterectomy.
commando o. commando procedure
concrete o.'s in the psychology of Piaget, a stage of development in thinking, occurring approximately between 7 and 11 years of age, during which a child becomes capable of reasoning about concrete situations.
Cotte's o. presacral neurectomy
Dana's o. posterior rhizotomy
Dandy o. See third ventriculostomy, trigeminal rhizotomy.
Daviel's o. extracapsular cataract extraction.
debulking o. excision of a major part of a malignant tumor which cannot be completely removed, so as to enhance the effectiveness of subsequent radio- or chemotherapy.
decompression o.'s See decompression.
Doyle's o. paracervical uterine denervation.
Dupuy-Dutemps o. a modified dacryocystorhinostomy for stenosis of the lacrimal duct.
Elliot's o. trephining of the eyeball at the corneoscleral margin to relieve tension in glaucoma.
Emmet's o. trachelorrhaphy
Esser o. See inlay graft.
Estes o. an o. for sterility in which a portion of an ovary is implanted on one uterine cornu.
Estlander o. use of an Estlander flap in plastic surgery of the lips.
fenestration o. a rarely used surgical procedure producing an opening from the external auditory canal to the membranous labyrinth to improve hearing in hearing impairment of the conduction type.
Filatov's o. obsolete eponym for penetrating keratoplasty.
filtering o. a surgical procedure for creation of a fistula between the anterior chamber of the eye and the subconjunctival space in treatment of glaucoma.
Finney's o. gastroduodenostomy which creates, by the technique of closure, a large opening to insure free emptying from the stomach.
flap o. 1. flap amputation 2. in dental surgery, an o. in which a portion of the mucoperiosteal tissues is surgically detached from the underlying bone or impacted tooth for better access and visibility in exploring the area covered by the tissue. See also flap.
Foley o. Foley Y-plasty pyeloplasty
Fontan o. Fontan procedure
formal o.'s in the psychology of Piaget, a stage of development in thinking, occurring approximately between 11 and 15 years of age, during which a child becomes capable of reasoning about abstract situations; reasoning at this stage is comparable to that of normal adults but less sophisticated.
Fothergill's o. Manchester o
Frazier-Spiller o. See trigeminal rhizotomy.
Fredet-Ramstedt o. pyloromyotomy
Freund's o. 1. total abdominal hysterectomy for uterine cancer; 2. chondrotomy to relieve Freund's anomaly.
Gigli's o. pubiotomy
Gilliam's o. an o. for retroversion of the uterus by suturing round ligaments to abdominal wall fascia.
Gillies' o. a technique for reducing fractures of the zygoma and the zygomatic arch through an incision in the temporal region above the hairline.
Gil-Vernet o. extended pyelotomy
Glenn's o. anastomosis between the superior vena cava and the right main pulmonary artery to increase pulmonary blood flow as a palliative correction for tricuspid atresia.
Graefe's o. 1. removal of cataract by a limbal incision with capsulotomy and iridectomy. Both operations were landmarks in the field of ophthalmic surgery; 2. iridectomy for glaucoma.
Gritti's o. Gritti-Stokes amputation
Halsted's o. 1. an o. for the radical correction of inguinal hernia; 2. radical mastectomy
Hartmann's o. resection of the rectosigmoid colon beginning at or just above the peritoneal reflexion and extending proximally, with closure of the rectal stump and end-colostomy.
Heaney's o. technique for vaginal hysterectomy.
Heller o. esophagomyotomy at the gastro-esophageal region.
Hill o. repair of hiatus hernia; narrowing the esophagogastric junction and attaching it to the right medial arcuate ligament.
Hoffa's o. in congenital dislocation of the hip, hollowing out the acetabulum and reduction of the head of the femur after severing the muscles inserted into the upper portion of the bone.
Hofmeister's o. partial gastrectomy with closure of a portion of the lesser curvature and retrocolic anastomosis of the remainder to jejunum.
Huggins' o. orchidectomy performed for palliation or cure of cancer of the prostate.castration (1);
Hummelsheim's o. transplantation of a normal ocular rectus muscle, to substitute for a paralyzed muscle.
Hunter's o. ligation of the artery proximal and distal to an aneurysm.
Indian o. Indian rhinoplasty
interval o. an o. performed during a period of quiescence or of intermission in the condition necessitating surgery.
Italian o. Italian rhinoplasty
Jacobaeus o. obsolete term for pleurolysis.
Jansen's o. an o. for frontal sinus disease, the lower wall and lower portion of the anterior wall being removed and the mucous membrane curetted away.
Kasai o. portoenterostomy
Kazanjian's o. surgical extension of the vestibular sulcus of edentulous ridges to increase their height and to improve denture retention. See also ridge extension.
Keen's o. removal of sections of the posterior branches of the spinal nerves to the affected muscles, and of the spinal accessory nerve, as a cure for torticollis.
Keller-Madlener o. an o. for treatment of gastric ulcer located in the proximal cardia that involves 75% gastrectomy and gastrojejunostomy.
Kelly's o. 1. correction of retroversion of the uterus by plication of uterosacral ligaments; 2. correction of urinary stress incontinence by vaginally placing sutures beneath the bladder neck.
Killian's o. an o. for frontal sinus disease in which the entire anterior wall is removed and the mucous membrane is curetted away; the ethmoid cells are scraped out through an opening in the nasal process of the maxillary bone, and the upper wall of the orbit is removed as well.
Koerte-Ballance o. operative anastomosis of the facial and hypoglossal nerves for the treatment of facial paralysis.
Kondoleon o. excision of strips of subcutaneous connective tissue for the relief of elephantiasis.
Kraske's o. removal of the coccyx and excision of the left wing of the sacrum in order to afford approach for resection of the rectum for cancer or stenosis.
Krönlein o. orbital decompression through the anterior lateral wall of the orbit.
Ladd's o. division of Ladd's band to relieve duodenal obstruction in malrotation of the intestine.
Lambrinudi o. a form of triple arthrodesis done in such a manner as to prevent foot drop, usually as occurs in poliomyelitis.
Laroyenne's o. puncture of Douglas pouch to evacuate the pus and to secure drainage in cases of pelvic suppuration.
Lash's o. removal of a wedge of the internal cervical os with suturing of the internal os into a tighter canal structure.
LeCompte o. LeCompte maneuver
Leriche's o. periarterial sympathectomy
Lisfranc's o. Lisfranc's amputation
Longmire's o. intrahepatic cholangiojejunostomy with partial hepatectomy for biliary obstruction.
Luc's o. Caldwell-Luc o
Madlener o. tubal sterilization by clamp and tie.
major o. an extensive, relatively difficult surgical procedure involving vital organs and/or in itself hazardous to life.
Manchester o. a vaginal o. for prolapse of the uterus, consisting of cervical amputation and parametrial fixation (cardinal ligaments) anterior to the uterus.Fothergill's o; [Manchester, England]
Mann-Williamson o. an o. performed on experimental animals (dogs) in research on peptic ulcer, the duodenum with its alkaline secretions being transplanted into the ileum and the cut end of the jejunum anastomosed to the pylorus; the animals develop ulcers in the jejunum which directly receives the gastric juice.
Marshall-Marchetti-Krantz o. an o. for urinary stress incontinence, performed retropubically.
Mason o. gastric bypass
Matas' o. obsolete term for aneurysmoplasty.
Mayo's o. an o. for the radical cure of umbilical hernia; the neck of the sac is exposed by two elliptical incisions, the gut is returned to the abdomen, the sac and adherent omentum are cut away, and the fascial edges of the opening are overlapped with mattress sutures.
McIndoe o. o. for the development of a neovagina using a split thickness skin graft over a vaginal mold.
McVay's o. repair of inguinal and femoral hernias by suture of the transversus abdominis muscle and its associated fasciae (transversus layer) to the pectineal ligament.
mika o. the establishment of a permanent fistula in the bulbous portions of the urethra in order to render the man incapable of procreating; said to be a practice among certain Australian aborigines. [Australian native term]
Mikulicz' o. excision of bowel in two stages: 1) exteriorizing the diseased area, suturing efferent and afferent limbs together, and closing the abdomen around them, after which the diseased part is excised; 2) at a later time, cutting the spur with an enterotome and closing the stoma extraperitoneally.
Miles' o. combined abdominoperineal resection for carcinoma of the rectum.Miles resection;
minor o. a surgical procedure of relatively slight extent and not in itself hazardous to life.
morcellation o. vaginal hysterectomy in which the uterus is removed in multiple pieces after being split or partitioned.
Motais' o. transplantation of the middle third of the tendon of the superior rectus muscle of the eyeball into the upper lid, between the tarsus and skin, to supplement the action of the levator muscle in ptosis.
Mules' o. evisceration of the eyeball followed by the insertion within the sclera of a spherical prosthesis to support an artificial eye.
Mustard o. correction, at the atrial level, of hemodynamic abnormality due to transposition of the great arteries by an intraatrial baffle to direct pulmonary venous blood through the tricuspid orifice into the right ventricle and the systemic venous blood through the mitral valve into the left ventricle.Mustard procedure;
Naffziger o. orbital decompression for severe malignant exophthalmos by removal of the lateral and superior orbital walls.
Nissen's o. fundoplication
Norton's o. extraperitoneal cesarean section by a paravesical approach.
Norwood's o. in infants with subaortic stenosis and tricuspid atresia; the pulmonary artery is divided and both ends are attached to the aorta, the distal end via a prosthetic graft.
Ogston-Luc o. an o. for frontal sinus disease; a skin incision is made from the inner third of the edge of the orbit toward the root of the nose or outward; the periosteum is pushed upward and outward, and the sinus is opened on the outer side of the median line; then a wide opening is made by curetting the nasofrontal duct, interior of the sinus, and anterior ethmoid cells.
Ogura o. orbital decompression by removal of the floor of the orbit through an opening made in the supradental (canine) fossa.
Ombrédanne o. a technique whereby the mobilized testis is brought down into the scrotum and through the scrotal septum, to be affixed to the tissues in the contralateral scrotal pouch.transseptal orchiopexy;
Payne o. a jejunoileal bypass for morbid obesity utilizing end-to-side anastomosis of the upper jejunum to the terminal ileum, with closure of the proximal end of the bypassed intestine.
plastic o. See plastic surgery.
Pólya's o. Pólya gastrectomy
Pomeroy's o. excision of a ligated portion of the fallopian tubes.
Porro o. cesarean hysterectomy
Potts' o. direct side-to-side anastomosis between aorta and pulmonary artery as a palliative procedure in congenital malformation of the heart.Potts' anastomosis;
pubovaginal o. operative procedure for urinary incontinence. A strip of tissue, usually autologous rectus abdominis fascia, is used to suspend or elevate bladder neck and posterior urethra toward pubic symphysis.
Putti-Platt o. a procedure for recurrent dislocation of shoulder joint.Putti-Platt procedure;
radical o. for hernia an o. by which the hernia is not only reduced, but the hernial defect is also repaired.
Ramstedt o. pyloromyotomy
Rastelli's o. an o. for transposition of the great arteries plus ventricular septal defect and LV outflow obstruction; employs an intraventricular tunnel repair and a rerouting valved extracardiac conduit.
Rastelli's o. for "anatomic" repair of transposition of the great arteries (ventriculoarterial discordance) with ventricular septal defect and left ventricular outflow tract obstruction; conduits are used to create left ventricular to aortic continuity and right ventricular to pulmonary artery continuity. All septal defects are obliterated as are any previously constructed palliative shunts.
Récamier's o. curettage of the uterus.
Ridell's o. removal of the entire anterior and inferior walls of the frontal sinus, for chronic inflammation of that cavity.
Roux-en-Y o. anastomosis of the distal end of the divided upper jejunum to the stomach, esophagus, biliary tract, or other structure and anastomosis of the proximal end to the side of the jejunum a little further distal.
Saenger's o. cesarean section followed by careful closure of the uterine wound by three tiers of sutures.
Schauta vaginal o. an extensive extirpation of the uterus and the adnexa, using the vaginal approach facilitated by Schuchardt's o.
Schönbein's o. the use of a flap of mucous membrane from the posterior wall of the pharynx to the soft palate closing off the flow of air from the nose to the mouth.
Schroeder's o. excision of diseased endocervical mucosa.
Schuchardt's o. a paravaginal rectal displacement incision, a surgical technique of making the upper vagina accessible for fistula closure or radical surgery via the vagina.
scleral buckling o. an o. performed in retinal detachment to indent the sclerochoroidal wall.
Scott o. a jejunoileal bypass for morbid obesity utilizing end-to-end anastomosis of the upper jejunum to the terminal ileum, with the bypassed intestine closed proximally and anastomosed distally to the colon.
second-look o. exploratory celiotomy within a year after apparently curative resection of intra-abdominal cancer, in patients with no sign or symptom of recurrence, to resect an occult tumor if present.
Senning o. an atrial switch o. for patients with transposition of the great arteries that employs a septal flap instead of excising the atrial septum as in the Mustard o., thus minimizing foreign material and allowing for growth.
seton o. an o. for advanced glaucoma; passage of a tube or seton into the anterior chamber to act as a wick.
Shirodkar o. a cerclage procedure done by purse-string suturing of an incompetent cervical os with a nonabsorbent suture material.
Sistrunk o. excision of the thyroglossal cyst and duct including the midportion of the hyoid bone through, or near, which the duct traverses.
Smith-Boyce o. anatrophic nephrotomy
Smith-Indian o. a surgical technique for removal of cataract within the capsule.Smith's o;
Smith-Robinson o. interbody spinal fusion through an anterior cervical approach.
Smith's o. Smith-Indian o
Soave o. endorectal pull-through for treatment of congenital megacolon.
Spinelli o. an o. splitting the anterior wall of the prolapsed uterus and reversing the organ preliminary to reduction.
stapes mobilization o. now infrequently used o. involving fracture of tissue immobilizing the stapes to restore hearing; especially used in patients with otosclerosis.
Stoffel's o. division of certain motor nerves for the relief of spastic paralysis.
Stookey-Scarff o. See third ventriculostomy.
Sturmdorf's o. conical removal of the endocervix.
subcutaneous o. an o., as for the division of a tendon, performed without incising the skin other than by a minute opening made by the entering knife.
Syme's o. Syme's amputation
tagliacotian o. Italian rhinoplasty
talc o. an obsolete o. in which magnesium silicate (talc) powder is applied to the epicardium to create a sterile granulomatous pericarditis and thus promote pericardial anastomoses with the coronary circulation.poudrage (2);
TeLinde o. modified radical hysterectomy
Thiersch's o. the application of a partial thickness skin graft.Thiersch's graft o;
Thiersch's graft o. Thiersch's o
Torek o. a two-stage o. for bringing down an undescended testicle.
Trendelenburg's o. a pulmonary embolectomy.
Urban's o. extended radical mastectomy, including en bloc resection of internal mammary lymph nodes, part of the sternum, and costal cartilages.
Waters' o. an extraperitoneal cesarean section with a supravesical approach.
Waterston o. a surgically created anastomosis between the pulmonary artery and the ascending aorta to palliate adult tetralogy of Fallot.
Webster's o. Baldy's o
Weir's o. obsolete eponym for appendicostomy.
Wertheim's o. a radical o. for carcinoma of the uterus in which as much as possible of the vagina is excised and there is wide lymph node excision.
Wheelhouse's o. obsolete term for external urethrotomy.
Whipple's o. pancreatoduodenectomy
Whitehead's o. excision of hemorrhoids by two circular incisions above and below involved veins, allowing normal mucosa to be pulled down and sutured to anal skin.



Copyright© 1995 Williams & Wilkins. All rights reserved.

operative operative (op´er-a-tiv)
1. Relating to, or effected by means of an operation. 2. Active or effective.



Copyright© 1995 Williams & Wilkins. All rights reserved.

operator operator (op´er-a-tor)
1. One who performs an operation or operates equipment. 2. In genetics, a sequence of DNA that interacts with a repressor of operon to control the expression of adjacent structural genes. See operator gene. 3. A symbol representing a mathematical operation. [L. worker, fr operor, to work]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opercular opercular (o-per´kyu-lar)
Relating to an operculum.



Copyright© 1995 Williams & Wilkins. All rights reserved.

operculated operculated (o-per´kyu-la-ted)
Provided with a lid (operculum); denoting members of the mollusk class Gastropoda (the snails), subclass Prosobranchiata (operculate snails), and the eggs of certain parasitic worms such as the digenetic trematodes (except the schistosomes) and the broad fish tapeworm, Diphyllobotrium latum.



Copyright© 1995 Williams & Wilkins. All rights reserved.

operculitis operculitis (o-perk-yu-lI´tis)
Originating under an operculum. [operculum + G. -itis, inflammation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

operculum operculum, gen. operculi, pl. opercula (o-per´kyu-lum, -lI, -la)
1. Anything resembling a lid or cover. 2. [NA] In anatomy, the portions of the frontal, parietal, and temporal lobes bordering the lateral sulcus and covering the insula. 3. Mucus sealing the endocervical canal of the uterus after conception has taken place. 4. In parasitology, the lid or caplike cover of the shell opening of operculated freshwater snails in the subclass Prosobranchiata, and of the eggs of certain trematode and cestode parasites. 5. The attached flap in the tear of retinal detachment. 6. The mucosal flap partially or completely covering an unerupted tooth. [L. cover or lid, fr. operio, pp. opertus, to cover]
o. il´ei ileal sphincter
occipital o. a portion of the occipital lobe of the brain demarcated by the simian fissure (sulcus lunatus cerebri) when present in humans.
trophoblastic o. the mushroom-shaped plug of fibrin that fills the aperture in the endometrium made by the implanting ovum.



Copyright© 1995 Williams & Wilkins. All rights reserved.

operon operon (op´er-on)
A genetic functional unit that controls production of a messenger RNA; it consists of an operator gene and two or more structural genes located in sequence in the cis position on one chromosome. [L. operor, to work, act, + -on]
Lac o. a collection of adjacent bacterial genes responsible for the entry and metabolism of lactose; contains the genes coding for three enzymes and is flanked by a repressor and a promoter region to control expression.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophiasis ophiasis (o-fI´a-sis)
A form of alopecia areata in which the loss of hair occurs in bands along the scalp margin partially or completely encircling the head. [G., fr. ophis, snake]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ophidia Ophidia (o-fid´e-a)
The snakes, a suborder of the class Reptilia, including the families Colubridae, Crotalidae, Elapidae, Hydrophyidae, and Viperidae. [G. ophidion, dim. of ophis, a serpent]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophidiasis ophidiasis (o´fi-dI´a-sis)
Poisoning by a snake.ophidism; [G. ophidion, dim. of ophis, a serpent]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophidiophobia ophidiophobia (o-fid´e-o-fo´be-a)
Morbid fear of snakes. [G. ophidion, a small snake, + phobos, fear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophidism ophidism (o´fid-izm)
ophidiasis



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophritis ophritis (of-rI´tis)
Dermatitis in the region of the eyebrows.ophryitis; [G. ophrys, eyebrow, + -itis, infammation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophryitis ophryitis (of-re-I´tis)
ophritis



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophryogenes ophryogenes (of´re-yo-jen-´enz)
Related to the eyebrows. [Mod. L., fr. G. ophrys, eyebrow, + suffix -genes, arising from]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophryon ophryon (of´re-on)
The point on the midline of the forehead just above the glabella (1).supranasal point, supraorbital point; [G. ophrys, eyebrow]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ophryoscolecidae Ophryoscolecidae (of´re-o-sko-les´i-de)
A family of ciliate protozoa occurring in the rumen and reticulum of ruminant animals, characterized by having cilia arranged in spiral membranelles around the mouth (adoral) and in some genera also in a dorsal (metoral) position. The most important genera are Entodinium, Diplodinium, Epidinium, and Ophryoscolex, which are thought to contribute to ruminant nutrition by converting cellulose in plant material ingested by the ruminant into readily digestible animal protein of their own bodies. [G. ophrys, eyebrow, + skolex, a worm]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophryosis ophryosis (of-re-o´sis)
Spasmodic twitching of the upper portion of the orbicularis palpebrarum muscle causing a wrinkling of the eyebrow. [G. ophrys, eyebrow, + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalm- ophthalm-
See ophthalmo-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmalgia ophthalmalgia (of´thal-mal´je-a)
oculodynia [ophthalmo- + G. algos, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmia ophthalmia (of-thal´me-a)
1. Severe, often purulent, conjunctivitis. 2. Inflammation of the deeper structures of the eye. [G.]
catarrhal o. a mild form of conjunctivitis with mucopurulent secretion.
caterpillar-hair o. o. nodosa
o. eczemato´sa obsolete term for phlyctenular conjunctivitis.
Egyptian o. trachoma
gonorrheal o. acute purulent conjunctivitis excited by Neisseria gonorrhoeae.blennophthalmia (2), blennorrhea conjunctivalis, gonorrheal conjunctivitis;
granular o. trachoma
infectious o. infectious bovine keratoconjunctivitis
metastatic o. 1. sympathetic o; 2. choroiditis in septicemia.
o. neonato´rum a conjunctival inflammation occurring within the first 10 days of life; causes include Neisseria gonorrhoeae, Staphylococcus, Streptococcus pneumoniae, and Chlamydia trachomatis.blennorrhea neonatorum, infantile purulent conjunctivitis, neonatal conjunctivitis;
o. niva´lis ultraviolet keratoconjunctivitis
o. nodo´sa the presence of nodular swellings on the conjunctiva, due to penetration of ocular tissues by the hairs of caterpillars.caterpillar-hair o;
periodic o. an acute iridocyclitis of horses, involving one or both eyes; it subsides only to recur at intervals of varying length and usually ends in blindness; the cause is uncertain but some have associated it with leptospires; does not appear to be contagious.moon blindness;
phlyctenular o. phlyctenular conjunctivitis
purulent o. purulent conjunctivitis, usually of gonorrheal origin.
spring o. vernal conjunctivitis
sympathetic o. a serous or plastic uveitis caused by a perforating wound of the uvea followed by a similar severe reaction in the other eye that may lead to bilateral blindness.transferred o;
transferred o. sympathetic o



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmic ophthalmic (of-thal´mik)
Relating to the eye.ocular (1); [G. ophthalmikos]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmic acid ophthalmic acid
A tripeptide occurring in lens, similar to glutathione but differing in the replacement of cysteine by a-amino-n-butyric acid (i.e., in the replacement of -SH by -CH3); a potent inhibitor of glyoxalase. Cf. norophthalmic acid.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmo- ophthalmo- , ophthalm-
Relationship to the eye. See also oculo-. [G. ophthalmos]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmodynamometer ophthalmodynamometer (of-thal´mo-dI-na-mom´e-ter)
An instrument to measure the blood pressure in the retinal vessels. [ophthalmo- + G. dynamis, power, + metron, measure]
Bailliart's o. an instrument used to measure the blood pressure of the central retinal artery; of value in diagnosing occlusion of the proximal carotid artery.
suction o. an o. with a suction disk which increases ocular pressure during ophthalmoscopic observation of the retinal artery.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmodynamometry ophthalmodynamometry (of-thal´mo-dI-na-mom´e-tre)
The measurement of blood pressure in the retinal vessels by means of an ophthalmodynamometer. [ophthalmo- + G. dynamis, power, + metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmolith ophthalmolith (of-thal´mo-lith)
dacryolith [ophthalmo- + G. lithos, stone]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmologist ophthalmologist (of-thal-mol´o-jist)
A specialist in ophthalmology.oculist;



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmology ophthalmology (of-thal-mol´o-je)
The medical specialty concerned with the eye, its diseases, and refractive errors. [ophthalmo- + G. logos, study]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmomalacia ophthalmomalacia (of-thal´mo-ma-la´she-a)
Abnormal softening of the eyeball. [ophthalmo- + G. malakia, softness]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmomelanosis ophthalmomelanosis (of-thal´mo-mel-a-no´sis)
Melanotic discoloration of the conjunctiva and adjoining tissues.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmometer ophthalmometer (of-thal-mom´e-ter)
keratometer [ophthalmo- + G. metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmomycosis ophthalmomycosis (of-thal´mo-mI-ko´sis)
Any disease of the eye or its appendages caused by a fungus. [ophthalmo- + G. mykes, fungus, + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmomyiasis ophthalmomyiasis (of-thal´mo-mI-I´a-sis)
ocular myiasis



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmopathy ophthalmopathy (of-thal-mop´a-the)
Any disease of the eyes.oculopathy; [ophthalmo- + G. pathos, suffering]
endocrine o. Graves' o
external o. any disease of the conjunctiva, cornea, or adnexa of the eye.
Graves' o. exophthalmos caused by increased water content of retro-ocular orbital tissues; associated with thyroid disease, usually hyperthyroidism.endocrine o., Graves' orbitopathy;
internal o. any disease of the internal structures of the eyeball.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmoplegia ophthalmoplegia (of-thal-mo-ple´je-a)
Paralysis of one or more of the ocular muscles. [ophthalmo- + G. plege, stroke]
chronic progressive external o. (CPEO) a specific type of slowly worsening weakness of the ocular muscles, usually associated with a pigmentary retinopathy. See Kearns-Sayre syndrome, oculopharyngeal dystrophy.ocular myopathy;
exophthalmic o. o. with protrusion of the eyeballs due to increased water content of orbital tissues incidental to thyroid disorders, usually hyperthyroidism.
o. exter´na paralysis affecting one or more of the extrinsic eye muscles.external o;
external o. o. externa
fascicular o. o. due to a lesion within the brainstem.
fibrotic o. [MIM*135700] o. that may be congenital in association with blepharoptosis in and autosomal dominant disorder.
o. inter´na paralysis affecting only the sphincter muscle of the pupil and the ciliary muscle.internal o;
internal o. o. interna
o. internuclea´ris o. in lesions of the medial longitudinal fasciculus, with failure of adduction in horizontal gaze but with retention of convergence.
nuclear o. o. due to a lesion of the nuclei of origin of the motor nerves of the eye.
orbital o. o. due to a lesion within the orbit.
Parinaud's o. Parinaud's syndrome
o. partia´lis incomplete o. involving only one or two of the extrinsic or intrinsic ocular muscles.
o. progressi´va progressive upper bulbar palsy, due to degeneration of the nuclei of the motor nerves of the eye.
o. tota´lis paralysis of both the extrinsic and intrinsic ocular muscles.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmoplegic ophthalmoplegic (of-thal-mo-ple´jik)
Relating to or marked by ophthalmoplegia.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmoscope ophthalmoscope (of-thal´mo-skop)
A device for studying the interior of the eyeball through the pupil.funduscope; [ophthalmo- + G. skopeo, to examine]
binocular o. an o. that provides a stereoscopic view of the fundus.
demonstration o. an o. by which the fundus may be seen simultaneously by more than one observer.
direct o. an instrument designed to visualize the interior of the eye, with the instrument relatively close to the subject's eye and the observer viewing an upright magnified image.
indirect o. an instrument designed to visualize the interior of the eye, with the instrument at arm's length from the subject's eye and the observer viewing an inverted image through a convex lens located between the instrument and the subject's eye.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmoscopic ophthalmoscopic (of´thal-mo-skop´ik)
Relating to examination of the interior of the eye.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmoscopy ophthalmoscopy (of-thal-mos´ko-pe)
Examination of the fundus of the eye by means of the ophthalmoscope.funduscopy;
direct o. o. performed with a direct ophthalmoscope.
indirect o. o. performed with an indirect ophthalmoscope.
o. with reflected light examination of that part of the fundus adjacent to an area illuminated by a sharply focused light.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmotrope ophthalmotrope (of-thal´mo-trop)
A model of the two eyes, to each of which are attached weighted cords pulling in the direction of the six extrinsic eye muscles; used to demonstrate the action of the ocular muscles singly or in various combinations. [ophthalmo- + G. tropos, a turning]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ophthalmovascular ophthalmovascular (of-thal´mo-vas´kyu-lar)
Relating to the blood vessels of the eye.



Copyright© 1995 Williams & Wilkins. All rights reserved.

-opia -opia
Vision. [G. ops, eye]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opianine opianine (o-pI´a-nen)
noscapine



Copyright© 1995 Williams & Wilkins. All rights reserved.

opianyl opianyl (o´pI-a-nil)
meconin



Copyright© 1995 Williams & Wilkins. All rights reserved.

opiate opiate (o´pe-at)
Any preparation or derivative of opium.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opine opine (o´pen)
A derivative of basic amino acids, produced by crown-gall tumors in plants.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opioid opioid (o´pe-oyd)
Originally, a term denoting synthetic narcotics resembling opiates but increasingly used to refer to both opiates and synthetic narcotics.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opiomelanocortin opiomelanocortin (o´pe-o-mel´a-no-kor´tin)
A linear polypeptide of the pituitary gland that contains in its sequence the sequences of endorphins, MSH, ACTH, and the like, which are split off enzymically; the nucleotide sequences coding has been determined for several species.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opipramol hydrochloride opipramol hydrochloride (o-pip´ra-mol)
4-[3-(5H-Dibenz[b.f ]azepin-5-yl)propyl]-1-piperazineethanol dihydrochloride; an antidepressant agent.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthenar opisthenar (o-pis´the-nar)
Dorsum of the hand. [G. back of the hand, from opisthen, behind, + thenar, palm of the hand]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthiobasial opisthiobasial (o-pis´the-o-ba´se-al)
Relating to both opisthion and basion; denoting a line connecting the two, or the distance between them.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthion opisthion (o-pis´the-on) [NA]
The middle point on the posterior margin of the foramen magnum, opposite the basion. [G. opisthios, posterior]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthionasial opisthionasial (o-pis´the-o-na´ze-al)
Relating to the opisthion and the nasion; denoting the distance between the two points.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opistho- opistho-
Backward, behind, dorsal. [G. opisthen, at the rear, behind]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthocheilia opisthocheilia , opisthochilia (op´is-tho-kI´le-a)
Recession of the lips. [opistho- + G. cheilos, lip]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthomastigote opisthomastigote (o-pis-tho-mas´ti-got)
Term now used instead of herpetomonad for the stage of development of certain insect and plant parasitizing flagellates to avoid confusion between the stage and the genus Herpetomonas. In this stage the flagellum arises from the kinetoplast located behind the nucleus and emerges from the anterior end of the organism; an undulating membrane is absent. [opistho- + G. mastix, whip]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthoporeia opisthoporeia (o-pis´tho-po-rI´a, -re´a)
Involuntary backward gait; frequently connected with parkinsonism. [opistho- + G. poreia, a walking, fr. poreuo, to go, walk]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthorchiasis opisthorchiasis (op´is-thor-kI´a-sis)
Infection with the Asiatic liver fluke, Opisthorchis viverrini, or other opisthorchids.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthorchid opisthorchid (op-is-thor´kid)
Common name for members of the family Opisthorchiidae.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Opisthorchiidae Opisthorchiidae (op´is-thor-ke´i-de)
A family of trematodes that includes the genera Opisthorchis and Clonorchis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Opisthorchis Opisthorchis (op-is-thor´kis)
Genus of digenetic trematodes (family Opisthorchiidae) found in the bile ducts or gallbladder of fish-eating mammals, birds, and fish. [opistho- + G. orchis, testis]
O. felin´eus the cat liver fluke, a species frequently found as a parasite of man in Eastern Europe, Siberia, India, Japan, and Southeast Asia; adults are lancet-shaped, thin, relatively transparent, and hermaphroditic, with sizes ranging from 7 to 12 by 2 to 3 mm; ingested eggs hatch in Bithynia snails, and cercariae encyst on various species of freshwater fish; man acquires the infection by ingesting raw or inadequately cooked fish; the parasites sometimes cause no evidence of disease, but cholangitis, biliary cirrhosis, and chronic pancreatitis may occur.
O. sinen´sis Clonorchis sinensis
O. viverri´ni a species closely related to O. felineus, very common in man in Thailand; causes opisthorchiasis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthotic opisthotic (op-is-tho´tik)
Behind the ear. [opistho- + G. ous (ot-), ear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthotonic opisthotonic (op-is-thot´o-nik, o-pis´tho-ton´ik)
Relating to or characterized by opisthotonos.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthotonoid opisthotonoid (op-is-thot´o-noyd)
Resembling opisthotonos.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opisthotonos opisthotonos , opisthotonus (op-is-thot´o-nus)
A tetanic spasm in which the spine and extremities are bent with convexity forward, the body resting on the head and the heels.tetanus dorsalis, tetanus posticus; [opistho- + G. tonos, tension, stretching]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Opitz Opitz
John M., U.S. pediatrician, *1935. See Smith-Lemli-O. syndrome.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opium opium (o´pe-um)
The air-dried milky exudation obtained by incising the unripe capsules of Papaver somniferum (family Papveraceae) or its variety, P. album. Contains some 20 alkaloids, including morphine, 9 to 16%; noscapine, 4 to 8%; codeine, 0.8 to 2.5%; papaverine, 0.5 to 2.5%; and thebaine, 0.5 to 2%. Used as an analgesic, hypnotic, and diaphoretic, and in diarrhea and spasmodic conditions.gum opium, meconium (2); [L. fr. G. opion, poppy-juice]
Boston o. o. so diluted after importation as barely to meet the official requirements.pudding o;
deodorized o. , denarcotized o. powdered o. treated with purified petroleum benzine which removes certain nauseating and odorous constituents.
granulated o. o. dried and reduced to a coarse powder; it contains 10 to 10.5% anhydrous morphine.
powdered o. dried and finely powdered o. containing 10% morphine.
pudding o. Boston o



Copyright© 1995 Williams & Wilkins. All rights reserved.

opo- opo-
The face; an eye. See also fascio-. 2. Juice, balm. [G. ops]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opobalsamum opobalsamum (op-o-bal´sa-mum)
balm of Gilead [G. opobalsamon, the juice of the balsam tree, fr. opos, juice, + balsamon]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opodidymus opodidymus (op-o-did´i-mus)
Conjoined twins with a single body having two heads fused at the back with partially separated facial regions. See conjoined twins, under twin. [G. ops, eye, face, + didymos, twin]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oppenheim Oppenheim
Hermann, Berlin neurologist, 1858-1919. See O.'s disease, reflex, syndrome; Ziehen-O. disease.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oppilation oppilation (op-i-la´shun)
Obstruction or closing of the pores. [L. oppilatio, fr. op-pilo (obp-), pp. -atus, to stop up, fr. pilo, to ram down]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oppilative oppilative (op-i-la´tiv)
Obstructive to any secretion.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opponens opponens (o-po´nens)
A name given to several muscles of the fingers or toes, by the action of which these digits are opposed to the others. The opponens muscles of the hands act at the carpometacarpal joints, cupping the palm; this enables flexion at the metacarpophalangeal joints to oppose the thumb to the small finger or vice versa. Although comparable muscles in the foot are called "opponens" no opposition occurs in the foot. [L. op-pono (obp-), pres. p. -ens, to place against, oppose]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opportunistic opportunistic (op´or-tu-nis´tik)
1. Denoting an organism capable of causing disease only in a host whose resistance is lowered, e.g., by other diseases or by drugs. 2. Denoting a disease caused by such an organism.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opposure opposure (op´po-shur)
Bringing together of tissue during suturing.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsin opsin
The protein portion of the rhodopsin molecule; at least three separate o.'s are located in cone cells.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsinogen opsinogen (op-sin´o-jen)
A substance that stimulates the formation of opsonin, such as the antigen contained in a suspension of bacteria used for immunization.opsogen; [opsonin + -gen]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsiuria opsiuria (op-se-u´re-a)
A more rapid excretion of urine during fasting than after a full meal. [G. opsi, late, + ouron, urine]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsoclonus opsoclonus (op´so-klo´nus)
Rapid, irregular, nonrhythmic movements of the eye in horizontal and vertical directions. [G. ops, opos, eye, + klonos, confused motion]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsogen opsogen (op´so-jen)
opsinogen



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsomania opsomania (op´so-ma´ne-a)
A longing for a particular article of diet, or for highly seasoned food. [G. opson, seasoning, + mania, frenzy]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsonic opsonic (op-son´ik)
Relating to opsonins or to their utilization.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsonin opsonin (op´so-nin)
A substance that binds to antigens, enhancing phagocytosis (e.g., C3b of the complement system). [G. opson, boiled meat, provisions, fr. hepso, to boil, + -in]
common o. normal o
immune o. specific o
normal o. that normally present in the blood, i.e., without stimulation by a known, specific antigen such as certain complement components; it is relatively thermolabile and reacts with various organisms.common o., thermolabile o;
specific o. antibodies formed in response to stimulation by a specific antigen, either as a result of an attack of a disease, or injections with a suitably prepared suspension of the specific microorganism.immune o., thermostable o;
thermolabile o. normal o
thermostable o. specific o



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsonization opsonization (op´so-nI-za´shun)
The process by which bacteria are altered in such a manner that they are more readily and more efficiently engulfed by phagocytes.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsonocytophagic opsonocytophagic (op´so-no-sI´to-fa´jik)
Pertaining to the increased efficiency of phagocytic activity of the leukocytes in blood that contains specific opsonin. [opsonin + G. kytos, a hollow (cell), + phago, to eat]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsonometry opsonometry (op-so-nom´e-tre)
Determination of the opsonic index or the opsonocytophagic activity.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsonophilia opsonophilia (op-so-no-fil´e-a)
The condition in which bacteria readily unite with opsonins, thereby sensitizing them for more effective phagocytosis. [opsonin + G. phileo, to love]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opsonophilic opsonophilic (op-so-no-fil´ik)
Pertaining to, characterized by, or resulting in opsonophilia.



Copyright© 1995 Williams & Wilkins. All rights reserved.

optic optic , optical (op´tik, op´ti-kal)
Relating to the eye, vision, or optics. [G. optikos]



Copyright© 1995 Williams & Wilkins. All rights reserved.

optician optician (op-tish´an)
One who practices opticianry.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opticianry opticianry (op-tish´an-re)
The professional practice of filling prescriptions for ophthalmic lenses, dispensing spectacles, and making and fitting contact lenses.



Copyright© 1995 Williams & Wilkins. All rights reserved.

optico- optico-
See opto-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opticociliary opticociliary (op´ti-ko-sil´e-ar-e)
Relating to the optic and ciliary nerves.



Copyright© 1995 Williams & Wilkins. All rights reserved.

opticopupillary opticopupillary (op´ti-ko-pyu´pi-lar-e)
Relating to the optic nerve and the pupil.



Copyright© 1995 Williams & Wilkins. All rights reserved.

optics optics (op´tiks)
The science concerned with the properties of light, its refraction and absorption, and the refracting media of the eye in that relation. [G. optikos, fr. ops, eye]
Nomarski o. an optical system for differential interference contrast microscopy.
schlieren o. an optical system, often used in diffusion and centrifugation studies, which observes the refractive index gradient in solutions containing macromolecules.



Copyright© 1995 Williams & Wilkins. All rights reserved.

optimism optimism (op´ti-mizm)
The tendency to look on the bright side of everything, to believe that there is good in everything. [L. optimus, best]
therapeutic o. a belief in the efficacy of drugs and other therapeutic agents in the treatment of diseases.



Copyright© 1995 Williams & Wilkins. All rights reserved.

optimum optimum (op´ti-mum)
The best or most suitable; e.g., denoting the dose of a remedy likely to give most benefit with fewest side effects, the temperature or pH at which an enzyme has maximal activity. [L. ntr. sing. of optimus, best]



Copyright© 1995 Williams & Wilkins. All rights reserved.

opto- opto- , optico-
Optical; optic; ocular. [G. optikos, optical, from ops, eye]



Copyright© 1995 Williams & Wilkins. All rights reserved.

optokinetic optokinetic (op´to-ki-net´ik)
See optokinetic nystagmus. [opto- + G. kinesis, movement]



Copyright© 1995 Williams & Wilkins. All rights reserved.

optomeninx optomeninx (op´to-me´ninks)
retina [opto- + G. meninx, membrane]



Copyright© 1995 Williams & Wilkins. All rights reserved.

optometer optometer (op-tom´e-ter)
An instrument for determining the refraction of the eye. [opto- + G. metron, measure]
objective o. refractometer



Copyright© 1995 Williams & Wilkins. All rights reserved.

optometrist optometrist (op-tom´e-trist)
One who practices optometry.



Copyright© 1995 Williams & Wilkins. All rights reserved.

optometry optometry (op-tom´e-tre)
1. The profession concerned with the examination of the eyes and related structures to determine the presence of vision problems and eye disorders, and with the prescription and adaptation of lenses and other optical aids or the use of visual training for maximum visual efficiency. 2. The use of an optometer.



Copyright© 1995 Williams & Wilkins. All rights reserved.

optomyometer optomyometer (op´to-mI-om´e-ter)
An instrument for determining the relative power of the extrinsic muscles of the eye. [opto- + G. mys, muscle, + metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

optotypes optotypes (op´to-tIps)
Test letters. See test types. [opto- + G. typos, type]



Copyright© 1995 Williams & Wilkins. All rights reserved.

OPV OPV
Abbreviation for oral poliovirus vaccine. See poliovirus vaccines, under vaccine.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ora ora, pl. orae (o´ra, o´re) [NA]
An edge or a margin. [L.]
o. serra´ta [NA] the serrated extremity of the optic part of the retina, located a little behind the ciliary body and marking the limits of the percipient portion of the membrane.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ora ora (o´ra)
Plural of L. os, the mouth. [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orad orad (ad-o´ral)
1. In a direction toward the mouth. 2. Situated nearer the mouth in relation to a specific reference point; opposite of aborad. [L. os, mouth, + ad, to]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oral oral (or´al)
Relating to the mouth. [L. os (or-), mouth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orale orale (o-ra´le)
A point at the lingual side of the alveolar termination of the premaxillary suture. [Mod. L. punctum orale, oral point, fr. L. os (or-), mouth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oral Hygiene Index (OHI) Oral Hygiene Index (OHI)
An index used in epidemiological studies of dental disease, to evaluate dental plaque and dental calculus separately.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orality orality (or-al´i-te)
In freudian psychology, a term used to denote the psychic organization derived from, and characteristic of, the oral period of psychosexual development.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oram Oram
S., 20th century English cardiologist. See Holt-O. syndrome.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orange orange (or´enj)
1. The fruit of the orange tree, Citrus aurantium (family Rutaceae). 2. A color between yellow and red in the spectrum. For individual orange dyes, see specific name. [O.F. orenge, fr. Ar. naranj, the initial n being absorbed in Fr. article une]
bitter o. peel the dried rind of the unripe but fully grown fruit; a flavoring agent.
bitter o. peel, dried the dried outer part of the pericarp of the ripe, or nearly ripe, fruit; it contains not less than 2.5% v/w of volatile oil.
bitter o. peel, fresh the outer part of the pericarp of the ripe, or nearly ripe, fruit; used to prepare the tincture and the syrup.
bitter o. peel oil a volatile oil obtained by expression from the fresh peel of the bitter o.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orange G orange G [C.I. 16230]
An azo dye, C16H10N2O7S2Na2, used as a cytoplasmic stain in histologic techniques.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orange wood orange wood
A soft wood used in dentistry for placement of bridges, crowns, etc. by biting pressure, also used as a burnishing point in the polishing of root surfaces.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Orbeli Orbeli
Leon A., Russian physiologist, 1882-1958. See O. effect.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbicular orbicular (or-bik´yu-lar)
Similar in form to an orb; circular in form. [L. orbiculus, a small disk, dim. of orbis, circle]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbiculare orbiculare (or-bik-yu-la´re)
lenticular process of incus [L., fr. orbiculus, a small disk]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbicularis orbicularis (or-bik´yu-la´ris)
1. Circular; denoting a circular or disk-shaped structure. 2. orbicularis muscle [L. fr. orbiculus, a small disk]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbiculus ciliaris orbiculus ciliaris (or-bik´yu-lus sil-e-ar´is) [NA]
The darkly pigmented posterior zone of the ciliary body continuous with the retina at the ora serrata.ciliary disk, ciliary ring, pars plana; [Mod. L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbit orbit (or´bit)
The bony cavity containing the eyeball and its adnexa; it is formed of parts of seven bones: the frontal, maxillary, sphenoid, lacrimal, zygomatic, ethmoid, and palatine bones.orbita [NA], eye socket, orbital cavity;



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbita orbita, gen. orbitae (or´bi-ta, -te) [NA]
orbit [L. a wheel-track, fr. orbis, circle]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbital orbital (or´bi-tal)
Relating to the orbits.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbitale orbitale (or-bi-ta´le)
In cephalometrics, the lowermost point in the lower margin of the bony orbit that may be felt under the skin. [L. of an orbit]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbitography orbitography (or´bi-tog´ra-fe)
Radiographic evaluation of the orbit. [L. orbita, orbit, + G. grapho, to write]
positive contrast o. o. with injection of a water soluble iodinated compound into the muscle cone or along the orbital floor.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbitonasal orbitonasal (or´bi-to-na´sal)
Relating to the orbit and the nose or nasal cavity.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbitonometer orbitonometer (or´bi-to-nom´e-ter)
An instrument that measures the resistance offered to pressing the eyeball backwards into its socket. [L. orbita, orbit, + G. metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbitonometry orbitonometry (or´bi-to-nom´e-tre)
Measurement by means of the orbitonometer.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbitopagus orbitopagus (or-bi-top´a-gus)
Unequal conjoined twins in which the parasite, usually very imperfectly developed, is attached at an orbit of the autosite. See conjoined twins, under twin.teratoma orbitae; [L. orbita, orbit, + G. pagos, something fixed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbitopathy orbitopathy
disease of the orbit and its contents.
Graves' orbitopathy Graves' ophthalmopathy



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbitosphenoid orbitosphenoid (or´bi-to-sfe´noyd)
Relating to the orbit and the sphenoid bone.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orbitotomy orbitotomy (or-bi-tot´o-me)
Surgical incision into the orbit. [L. orbita, orbit, + tome, a cutting]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Orbivirus Orbivirus (or´bi-vI-rus)
A genus of viruses of vertebrates (family Reoviridae) that multiply in insects, including certain viruses formerly included with the arboviruses. They are antigenically distinct from other groups of viruses and are characterized by an indistinct but rather large outer layer of capsomeres which give the appearance of rings (hence the name). The genus includes, among others, Colorado tick fever virus of man, bluetongue virus of sheep, and African horse sickness virus. [L. orbis, ring, + virus]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orcein orcein (or´se-in) [old C.I. 1242]
A natural dye derived from orcinol by treatment with air and ammonia, which as a purple dye complex is used in various histologic staining methods.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchectomy orchectomy (or-kek´to-me)
orchiectomy



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchella orchella (or-kel´a) [old C.I. 1242]
archil



Copyright© 1995 Williams & Wilkins. All rights reserved.

orcheo- orcheo-
See orchio-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchi- orchi- , orchido- , orchio-
The testes. [G. orchis, testis]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchialgia orchialgia (or-ke-al´je-a)
Pain in the testis.orchiodynia, orchioneuralgia, testalgia; [orchi- + G. algos, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchichorea orchichorea (or´ke-ko-re´a)
Involuntary rising and falling movements of the testis. [orchi- + G. choreia, a dance]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchidectomy orchidectomy (or-ki-dek´to-me)
orchiectomy



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchidic orchidic (or-kid´ik)
Relating to the testis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchiditis orchiditis (or-ki-dI´tis)
orchitis



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchido- orchido-
See orchi-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchidometer orchidometer (or-ki-dom´e-ter)
1. A caliper device used to measure the size of testes. 2. A set of sized models of testes for comparison of testicular development. [orchido- + G. metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchidoptosis orchidoptosis (or´ki-dop-to´sis)
Ptosis of the male gonads. [orchido- + G. ptosis, a falling]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchidorraphy orchidorraphy (or-ki-dor´a-fe)
orchiopexy



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchiectomy orchiectomy (or-ke-ek´to-me)
Removal of one or both testes.orchectomy, orchidectomy, testectomy; [orchi- + G. ektome, excision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchiepididymitis orchiepididymitis (or´ke-ep´i-did´i-mI´tis)
Inflammation of the testis and epididymis. [orchi- + epididymis, + G. -itis, inflammation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchil orchil (or´kil) [old C.I. 1242]
archil



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchio- orchio-
See orchi-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchiocele orchiocele (or´ke-o-sel)
A testis retained in the inguinal canal. [orchio- + G. kele, hernia, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchiococcus orchiococcus (or´ke-o-kok´us)
An old term for any Gram-negative diplococcus that resembles the gonococcus but is more easily cultivated on ordinary media; it is sometimes found in vaginal secretions. Such bacteria are now classified as species of Neisseria, along with N. gonorrhoeae. [orchio- + G. kokkos, berry (coccus)]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchiodynia orchiodynia (or´ke-o-din´e-a)
orchialgia [orchi- + G. odyne, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchioncus orchioncus (or-ke-ong´kus)
A neoplasm of the testis. [orchio- + G. onkos, bulk, mass]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchioneuralgia orchioneuralgia (or´ke-o-nu-ral´je-a)
orchialgia [orchio- + G. neuron, nerve, + algos, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchiopathy orchiopathy (or-ke-op´a-the)
Disease of a testis. [orchio- + G. pathos, suffering]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchiopexy orchiopexy (or´ke-o-pek´se)
Surgical treatment of an undescended testicle by freeing it and implanting it into the scrotum.cryptorchidopexy, orchidorraphy, orchiorrhaphy; [orchio- + G. pexis, fixation]
transseptal o. Ombrédanne operation



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchioplasty orchioplasty (or´ke-o-plas-te)
Surgical reconstruction of the testis. [orchio- + G. plastos, formed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchiorrhaphy orchiorrhaphy (or-ke-or´a-fe)
orchiopexy [orchio- + G. rhaphe, a suture]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchiotherapy orchiotherapy (or´ke-o-thar´a-pe)
Treatment with testicular extracts.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchiotomy orchiotomy (or-ke-ot´o-me)
Incision into a testis.orchotomy; [orchio- + G. tome, incision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchis orchis, pl. orchises (or´kis, or´ki-sez)
testis [G. testis, an orchid]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchitic orchitic (or-kit´ik)
Denoting orchitis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchitis orchitis (or-kI´tis)
Inflammation of the testis.orchiditis, testitis; [orchi- + G. -itis, inflammation]
o. parotid´ea o. associated with mumps.
traumatic o. simple inflammation of the testis caused by mechanical injury.
o. variolo´sa o. complicating smallpox.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orchotomy orchotomy (or-kot´o-me)
orchiotomy



Copyright© 1995 Williams & Wilkins. All rights reserved.

orcin orcin (or´sin)
orcinol



Copyright© 1995 Williams & Wilkins. All rights reserved.

orcinol orcinol (or´sin-ol)
3,5-dihydroxytoluene;the parent substance of the natural dye orcein, obtained from certain colorless lichens (Lecanora tinctoria, Rocella tinctoria) by treatment with boiling water; used as an external antiseptic in various skin diseases and in chemistry as a reagent for pentoses.5-methylresorcinol, orcin;



Copyright© 1995 Williams & Wilkins. All rights reserved.

orciprenaline sulfate orciprenaline sulfate (or-si-pren´a-len)
metaproterenol sulfate



Copyright© 1995 Williams & Wilkins. All rights reserved.

ORD ORD
Abbreviation for optical rotatory dispersion.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ord Ord
Symbol for orotidine.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ordeal bean ordeal bean (or´de-al)
physostigma



Copyright© 1995 Williams & Wilkins. All rights reserved.

order order (or´der)
1. In biological classification, the division just below the class (or subclass) and above the family. 2. In a reaction, o. is the sum of the exponents of all the concentration terms in that reaction's rate expression. For example, for the natural decomposition of nitrogen pentoxide, the rate expression is v = -d[N2O5]/dt = k1[N2O5]. Thus, this is a first-order reaction. A reaction involving two different compounds is often a second-order reaction (but not necessarily so). Pseudo-first-order reactions are multi-order reactions in which one of the reactants is in substoichiometric amounts. Cf. molecularity. [L. ordo, regular arrangement]
pecking o. in some species of birds and primates the establishment of a graded dominance in members of a group by the use of aggression.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ordered ordered (ord´erd)
ordered mechanism



Copyright© 1995 Williams & Wilkins. All rights reserved.

orderly orderly (or´der-le)
An attendant in a hospital unit who assists in the care of patients.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ordinate ordinate (or´di-nat)
In a plane cartesian coordinate system, the vertical axis (y). Cf. abscissa.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orectic orectic (o-rek´tik)
Pertaining to or characterized by orexia.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orexia orexia (o-rek´se-a)
1. The affective and conative aspects of an act, in contrast to the cognitive aspect. 2. appetite [G. orexis, appetite]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orexigenic orexigenic (o-rek-si-jen´ik)
Appetite-stimulating.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orf orf
A specific disease of sheep and goats, caused by the orf virus. This virus is transmissible to man and characterized by vesiculation and ulceration of the infected site.contagious ecthyma, contagious pustular dermatitis, scabby mouth, soremouth; [O.E. orfcwealm, murrain, fr. orf, cattle, + cwealm, destruction]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organ organ (or´gan)
Any part of the body exercising a specific function, as of respiration, secretion, digestion.organum [NA], organon; [L. organum, fr. G. organon, a tool, instrument]
accessory o.'s 1. supernumerary o.'s 2. accessory o.'s of the eye
accessory o.'s of the eye the eyelids, with lashes and eyebrows, lacrimal apparatus, conjunctival sac, and extrinsic muscles of the eyeball.organa oculi accessoria [NA], accessory o.'s (2), accessory visual apparatus, adnexa oculi, appendages of eye;
annulospiral o. annulospiral ending
auditory o. archaic term for gustatory o.
Chievitz' o. a normal epithelial structure, possibly a neurotransmitter, found at the angle of the mandible with branches of the buccal nerve.
circumventricular o.'s four small areas in or near the base of the brain that have fenestrated capillaries and are outside the blood-brain barrier. They are neurohypophysis, area postrema, organum vasculosum of the lamina terminalis and subfornical organ (SFO). The neurohypophysis is a neurohemal organ. The other three are chemoreceptors: area postrema triggers vomiting in response to chemical changes in plasma, organum vasculosum of the lamina terminalis senses osmolality and alters vasopressin secretion and SFO initiates drinking in response to angiotensin II.
Corti's o. spiral o
critical o. the o. or physiologic system that for a given source of radiation would first reach its legally defined maximum permissible radiation exposure as the dose of radiopharmaceutical is increased; e.g., the kidney is the critical o. when 197Hg-chlormerodrin is given.
enamel o. a circumscribed mass of ectodermal cells budded off from the dental lamina; it becomes cup-shaped and develops on its internal face the ameloblast layer of cells that produce the enamel cap of a developing tooth.
end o. the special structure containing the terminal of a nerve fiber in peripheral tissue such as muscle, tissue, skin, mucous membrane, or glands. See also ending.
external female genital o.'s the external feminine genital o.'s, the vulva and clitoris.organa genitalia feminina externa;
external male genital o.'s the external masculine genital o.'s, the penis and scrotum.organa genitalia masculina externa;
floating o. wandering o
flower-spray o. of Ruffini flower-spray ending
genital o.'s the organs of reproduction or generation, external and internal.organa genitalia [NA], genitalia, genitals;
Golgi tendon o. a proprioceptive sensory nerve ending embedded among the fibers of a tendon, often near the musculotendinous junction; it is compressed and activated by any increase of the tendon's tension, caused either by active contraction or passive stretch of the corresponding muscle.neurotendinous o., neurotendinous spindle;
gustatory o. located in the papillae of the mucous membrane of the tongue, chiefly in the vallate papillae.organum gustus [NA], o. of taste;
o. of hearing cochlear labyrinth
internal female genital o.'s the internal feminine genital organs, the ovaries, uterine tubes, uterus, and vagina.organa genitalia feminina interna;
internal male genital o.'s the internal masculine genital organs, the testes, epididymides, deferent ducts, seminal vesicles, prostate, and bulbourethral glands.organa genitalia masculina interna;
intromittent o. penis
Jacobson's o. vomeronasal o
lateral line sense o. a structure in fish consisting of a long groove or canal extending along each side of the trunk and tail and branching in the head region; the groove or tube is lined with neuroepithelial cells, some of which are in groups known as neuromasts; its function appears to be the detection of vibrations of low frequency.neuromast o;
neurohemal o.'s brain areas from which substances enter blood e.g., the neurohypophysis from which oxytocin and vasopressin enter blood.
neuromast o. lateral line sense o
neurotendinous o. Golgi tendon o
olfactory o. the olfactory region in the superior portion of the nasal cavity.organum olfactus [NA], o. of smell;
ptotic o. wandering o
o. of Rosenmüller epoöphoron
sense o.'s the organs of special sense, including the eye, ear, olfactory organ, taste organs, and the accessory structures associated with these organs.organa sensuum [NA];
o. of smell olfactory o
spiral o. a prominent ridge of highly specialized epithelium in the floor of the cochlear duct overlying the basilar membrane of cochlea, containing one inner row and three outer rows of hair cells, or cells of Corti (the auditory receptor cells innervated by the cochlear nerve) supported by various columnar cells: the pillars of Corti, cells of Hensen, and cells of Claudius; the spiral o. is partly overhung by an awning-like shelf, the tectorial membrane, the free marginal zone of which is covered by a gelatinous substance in which the stereocilia of the outer hair cells are embedded.organum spirale [NA], acoustic papilla, Corti's o;
subcommissural o. a microscopic organ, made up of columnar ciliated ependymal cells, located in the cerebral aqueduct beneath the posterior commissure of the brain; it is believed to have a neurosecretory function.
subfornical o. (SFO) the intercolumnar tubercle. One of the circumventricular o.'s. SFO has fenestrated capillaries and is outside the blood-brain barrier. It is thought to be a chemoreceptor zone involving in cardiovascular regulation.
supernumerary o.'s o.'s exceeding the normal number, which may develop from multiple foci of organization in an organ-formative field larger (originally) than that of the definitive main o.; such o.'s are aberrant but frequently not a cause of disease; illness may persist if they are left in the body after therapeutic removal of the main o., e.g., accessory spleen.accessory o.'s (1);
tactile o. o. of touch
target o. a tissue or o. upon which a hormone exerts its action; generally, a tissue or organ with appropriate receptors for a hormone.target (3);
o. of taste gustatory o
o. of touch any one of the sensory end o.'s.organum tactus, tactile o;
urinary o.'s organs involved with the formation, storage, and excretion of urine.organa urinaria [NA];
vestibular o. collective term for the utricle, saccule, and semicircular ducts of the membranous labyrinth, each having a single patch of ciliated receptor epithelium innervated by the vestibular nerve: macula of sacculus, macula of utriculus, and cristae of the semicircular ducts.
vestibulocochlear o. the external, middle, and internal ear.organum vestibulocochleare [NA];
vestigial o. a rudimentary structure in humans corresponding to a functional structure or o. in the lower animals.
o. of vision visual o
visual o. the eye and its adnexa.organum visus [NA], o. of vision;
vomeronasal o. a fine vestigal horizontal canal, ending in a blind pouch, in the mucous membrane of the nasal septum, beginning just behind and above the incisive duct; a structure which usually regresses after the 6th month of gestation. In many lower animals if functions as an accessory olfactory organ.organum vomeronasale [NA], Jacobson's o;
wandering o. an o. with loose attachments, permitting its displacement.floating o., ptotic o;
Weber's o. prostatic utricle
o.'s of Zuckerkandl para-aortic bodies, under body



Copyright© 1995 Williams & Wilkins. All rights reserved.

organa organa (or´ga-na)
Plural of organum.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organelle organelle (or´ga-nel)
One of the specialized parts of a protozoan or tissue cell; these subcellular units include mitochondria, the Golgi apparatus, nucleus and centrioles, granular and agranular endoplasmic reticulum, vacuoles, microsomes, lysosomes, plasma membrane, and certain fibrils, as well as plastids of plant cells.cell o., organoid (3); [G. organon, organ, + Fr. -elle, dim. suffix, fr. L. -ella]
cell o. organelle
paired o.'s rhoptry



Copyright© 1995 Williams & Wilkins. All rights reserved.

organic organic (or-gan´ik)
1. Relating to an organ. 2. Relating to or formed by an organism. 3. Organized; structural. 4. See organic compound. [G. organikos]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organicism organicism (or-gan´i-sizm)
A theory that attributes all diseases, in particular, all mental disorders, as organic in origin.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organicist organicist (or-gan´i-sist)
One who believes in, or subscribes to the views of, organicism.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organidin organidin
iodinated glycerol



Copyright© 1995 Williams & Wilkins. All rights reserved.

organism organism (or´ga-nizm)
Any living individual, whether plant or animal, considered as a whole.
calculated mean o. (CMO) a hypothetical o. whose characters are the means of both the positive and negative characters of the o.'s which belong to the same taxon as the CMO, as opposed to the hypothetical mean. o.
defective o. auxotrophic mutant
fastidious o. a bacterial organism having complex nutritional requirements.
hypothetical mean o. (HMO) a hypothetical o. whose characters are the means of the positive characters of the organisms which belong to the same taxon as the HMO, as opposed to the calculated mean o.
pleuropneumonia-like o.'s (PPLO) the original name given to a group of bacteria which did not possess cell walls; these o.'s, isolated from man and other animals, soil, and sewage, are now assigned to the order Mycoplasmatales.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organization organization (or´gan-i-za´shun)
1. An arrangement of distinct but mutually dependent parts. 2. The conversion of coagulated blood, exudate, or dead tissue into fibrous tissue.
preferred provider o. (PPO) a health care delivery model which uses a panel of eligible physicians.
pregenital o. in psychoanalysis, the o. or arrangement of the libido in the stages prior to that of genital primacy.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organize organize (or´gan-Iz)
To provide with, or to assume, a structure.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organizer organizer (or´gan-I-zer)
1. Originally applied to a group of cells on the dorsal lip of the blastopore, which induce differentiation of cells in the embryo and control growth and development of adjacent parts. 2. Any group of cells having such a controlling influence, the effects being brought about through the action of an evocator.
nucleolar o. the region of the satellites on the acrocentric chromosomes that is active in nucleolus formation.nucleolar zone, nucleolus o;
nucleolus o. nucleolar o
primary o. the o. situated on the dorsal lip of the blastopore.
procentriole o. deuterosome



Copyright© 1995 Williams & Wilkins. All rights reserved.

organo- organo-
Organ; organic. [G. organon]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organoaxial organoaxial (or-ga´no-aks´e-al)
Rotation around the long axis of the organ; a type of gastric volvulus.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organoferric organoferric (or´ga-no-far´ik)
Relating to an organic compound containing iron.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organogel organogel (or-gan´o-jel)
A hydrogel with an organic liquid instead of water as the dispersion means.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organogenesis organogenesis (or´ga-no-jen´e-sis)
Formation of organs during development.organogeny; [organo- + G. genesis, origin]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organogenetic organogenetic , organogenic (or´ga-no-je-net´ik, -jen´ik)
Relating to organogenesis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organogeny organogeny (or-gan-oj´e-ne)
organogenesis



Copyright© 1995 Williams & Wilkins. All rights reserved.

organography organography (or´ga-nog´ra-fe)
A treatise on, or description of, the organs of the body. [organo- + G. graphe, a writing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organoid organoid (or´ga-noyd)
1. Resembling in superficial appearance or in structure any of the organs or glands of the body. 2. Composed of glandular or organic elements, and not of a single tissue; pertaining to certain neoplasms (e.g., an adenoma) that contain cytologic and histologic elements arranged in a pattern that closely resembles or is virtually identical to a normal organ. See also histoid. 3. organelle [organo- + G. eidos, resemblance]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organoleptic organoleptic (or´ga-no-lep´tik)
1. Stimulating any of the organs of sensation. 2. Susceptible to a sensory stimulus. [organo- + G. leptikos, disposed to accept]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organology organology (or-ga-nol´o-je)
Branch of science concerned with the anatomy, physiology, development, and functions of the various organs. [organo- + G. logos, study]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organoma organoma (or-ga-no´ma)
Obsolete term for a neoplasm that contains cytologic and histologic elements in such an arrangement that specific types of tissue, e.g., thyroid glands, intestinal mucosa, ovarian stroma and follicles, may be identified in various parts. See also teratoma. [organo- + G. -oma, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organomegaly organomegaly (or´ga-no-meg´a-le)
visceromegaly



Copyright© 1995 Williams & Wilkins. All rights reserved.

organomercurial organomercurial (or-gan´o-mer-kyu´re-al)
Any organic mercurial compound; e.g., merbromin, thimerosal.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organometallic organometallic (or´ga-no-me-tal´ik)
Denoting an organic compound containing one or more metallic atoms in its structure.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organon organon, pl. organa (or´ga-non, or´ga-na)
organ [G. organ]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organonomy organonomy (or-ga-non´o-me)
The body of laws regulating the life processes of organized beings. [organo- + G. nomos, law]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organonymy organonymy (or´ga-non´i-me)
The nomenclature of the organs of the body, as distinguished from toponymy. [organo- + G. onyma, name]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organopathy organopathy (or-ga-nop´a-the)
Any disease especially affecting one of the organs of the body. [organo- + G. pathos, suffering]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organopexy organopexy , organopexia (or´ga-no-pek-se, -pek´se-a)
Fixation by suture or otherwise of a floating or ptotic organ. [organo- + G. pexis, fixation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organophilic organophilic (or´ga-no-fil´ik)
Pertaining to organophilicity.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organophilicity organophilicity (or´ga-no-fi-li´si-te)
Attraction of nonpolar substances (organic molecules) to each other.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organophosphates organophosphates (or-ga-no-fos´fats)
A series of phosphorus-containing organic compounds usually also containing a halide ion which reacts with cholinesterase. Organophosphates phosphorylate cholinesterase and thus irreversibly inhibit it. Used as insecticides; have also been used as war gases.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organosol organosol (or-gan´o-sol)
A hydrosol with an organic liquid instead of water as the dispersion means.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organotaxis organotaxis (or´ga-no-tak´sis)
The tendency to migrate to a certain organ selectively. [organo- + G. taxis, orderly arrangement]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organotherapy organotherapy (or´ga-no-thar´a-pe)
Treatment of disease by preparations made from animal organs; now frequently by synthetic preparations instead of extracts of a gland.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organotrophic organotrophic (or´ga-no-trof´ik)
1. Pertaining to the nourishment of an organ. 2. Pertaining to a microorganism that uses organic sources as a reducing power. [organo- + G. trophe, nourishment]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organotropic organotropic (or´ga-no-trop´ik)
Pertaining to or characterized by organotropism.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organotropism organotropism (or-ga-not´ro-pizm)
The special affinity of particular drugs, pathogens, or metastatic tumors for particular organs or their component parts. Cf. parasitotropism. organotropy; [organo- + G. trope, a turning]



Copyright© 1995 Williams & Wilkins. All rights reserved.

organotropy organotropy (or-ga-not´ro-pe)
organotropism



Copyright© 1995 Williams & Wilkins. All rights reserved.

organ-specific organ-specific
Denoting or pertaining to a serum produced by the injection of the cells of a certain organ or tissue that, when injected into another animal, destroys the cells of the corresponding organ.



Copyright© 1995 Williams & Wilkins. All rights reserved.

organum organum, pl. organa (or´ga-num, or´ga-na) [NA]
organ, organ [L. tool, instrument]
o. audi´tus archaic term for vestibulocochlear organ.
or´gana genita´lia [NA] genital organs, under organ
organa genita´lia femini´na exter´na external female genital organs, under organ
organa genita´lia femini´na inter´na internal female genital organs, under organ
organa genita´lia masculi´na exter´na external male genital organs, under organ
organa genita´lia masculi´na inter´na internal male genital organs, under organ
o. gus´tus [NA] gustatory organ
or´gana oc´uli accesso´ria [NA] accessory organs of the eye, under organ
o. olfac´tus [NA] olfactory organ
or´gana sen´suum [NA] sense organs, under organ
o. spira´le [NA] spiral organ
o. tac´tus organ of touch
or´gana urina´ria [NA] urinary organs, under organ
o. vestibulocochlea´re [NA] vestibulocochlear organ
o. vi´sus [NA] visual organ
o. vomeronasa´le [NA] vomeronasal organ



Copyright© 1995 Williams & Wilkins. All rights reserved.

orgasm orgasm (or´gazm)
The acme of the sexual act.climax (2); [G. orgao, to swell, be excited]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orgasmic orgasmic , orgastic (or-gaz´mik, -gas´tik)
Relating to, characteristic of, or tending to produce an orgasm.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orientation orientation (or-e-en-ta´shun)
1. The recognition of one's temporal, spatial, and personal relationships and environment. 2. The relative position of an atom with respect to one to which it is connected, i.e., the direction of the bond connecting them. [Fr. orienter, to set toward the East, therefore in a definite position]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orientomycin orientomycin (or´e-en-to-mI´sin)
cycloserine



Copyright© 1995 Williams & Wilkins. All rights reserved.

orifice orifice (or´i-fis)
Any aperture or opening.orificium [NA]; [L. orificium]
anal o. anus
aortic o. the opening from the left ventricle into the ascending aorta; it is guarded by the aortic valve.ostium aortae [NA], aortic ostium;
cardiac o. the trumpet-shaped opening of the esophagus into the stomach.ostium cardiacum [NA], cardiac opening, esophagogastric o;
esophagogastric o. cardiac o
o. of external acoustic meatus opening of external acoustic meatus
external urethral o. 1. the slitlike opening of the urethra in the glans penis; 2. the external orifice of the urethra (in the female) in the vestibule, usually upon a slight elevation, the papilla urethrae.ostium urethrae externum [NA], external opening of urethra, meatus urinarius, orificium urethrae externum;
gastroduodenal o. pyloric o
golf-hole ureteral o. a retracted funnel-shaped condition of the ureteral o. in the wall of the bladder, due often to tuberculosis or a secondary sclerosis of the ureter.
ileocecal o. the opening of the terminal ileum into the large intestine at the transition between the cecum and the ascending colon.ostium ileocecale [NA], ileocecal opening;
o. of inferior vena cava opening of inferior vena cava
o. of internal acoustic meatus opening of internal acoustic meatus
internal urethral o. the internal opening or orifice of the urethra, at the anterior and inferior angle of the trigone.ostium urethrae internum [NA], internal urethral opening;
mitral o. an atrioventricular opening which leads from the left atrium into the left ventricle of the heart.ostium atrioventriculare sinistrum [NA], ostium arteriosum;
pulmonary o. opening of pulmonary trunk
pyloric o. the opening between the stomach and the superior part of the duodenum.ostium pyloricum [NA], gastroduodenal o;
root canal o. an opening in the pulp chamber leading to the root canal.
o. of superior vena cava opening of superior vena cava
tricuspid o. an atrioventricular opening which leads from the right atrium into the right ventricle of the heart.ostium atrioventriculare dextrum [NA], ostium venosum cordis;
ureteric o. the opening of the ureter in the bladder, situated one at each lateral angle of the trigone; wide gaping of the o. usually indicates vesicoureteral reflux.ostium ureteris [NA], orificium ureteris, ureteral meatus, ureteral opening;
vaginal o. the narrowest portion of the canal, in the floor of the vestibule posterior to the urethral orifice.ostium vaginae [NA], orificium vaginae, vaginal opening;



Copyright© 1995 Williams & Wilkins. All rights reserved.

orificial orificial (or-i-fish´al)
Relating to an orifice of any kind.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orificium orificium, pl. orificia (or-i-fish´e-um, -a) [NA]
orifice, orifice [L.]
o. exter´num u´teri external os of uterus
o. inter´num u´teri isthmus of uterus
o. ure´teris ureteric orifice
o. ure´thrae exter´num external urethral orifice
o. vagi´nae vaginal orifice



Copyright© 1995 Williams & Wilkins. All rights reserved.

origanum oil origanum oil (o-rig´a-num)
The volatile oil (which contains carvacrol) obtained from various species of Origanum (family Labiatae); used as a rubefacient, as a constituent in veterinary liniments, and in microscopic techniques.



Copyright© 1995 Williams & Wilkins. All rights reserved.

origin origin (or´i-jin)
1. The less movable of the two points of attachment of a muscle, that which is attached to the more fixed part of the skeleton. 2. The starting point of a cranial or spinal nerve. The former have two o.'s: the ental o. , deep o. , or real o. , the cell group in the brain or medulla, whence the fibers of the nerve begin, and the ectal o. , superficial o. , or apparent o. , the point where the nerve emerges from the brain. [L. origo, source, beginning, fr. orior, to rise]
o. of replication a sequence of the bacterial genome required for the initiating of a replicating fork by leading strand synthesis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orizaba jalap root orizaba jalap root (o-riz´a-ba ja´lap)
ipomea



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ormond Ormond
John K., U.S. urologist, *1886. See O.'s disease.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Orn Orn
Symbol for ornithine or its radical.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ornate ornate (or´nat)
A term that refers to the patterning of the scutum (gray or white markings on a dark background) in ixodid ticks. [L. ornatus, decorated]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ornish Ornish
Dean, U.S. physician, *1953. See O. reversal diet.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ornithine (Orn) ornithine (Orn) (or´ni-then, -thin)
NH2(CH2)3CH(NH2)COOH; 2,5-Diaminovaleric acid;the l-isomer is the amino acid formed when l-arginine is hydrolyzed by arginase; not a constituent of proteins, but an important intermediate in the urea cycle; elevated levels seen in certain defects of the urea cycle.
o. acetyltransferase glutamate acetyltransferase
o. delta-aminotransferase an enzyme that will reversibly catalyze the reaction of a-ketoglutarate and l-o. to form l-glutamate and l-glutamate gamma-semialdehyde; a deficiency of this enzyme will result in gyrate atrophy of the choroid and retina.o. transaminase;
o. carbamoyltransferase an enzyme catalyzing formation of l-citrulline and orthophosphate from l-o. and carbamoyl phosphate; a part of the urea cycle; a deficiency of this enzyme will result in ammonia intoxication and impaired urea formation.o. transcarbamoylase;
o. decarboxylase an enzyme catalyzing the decarboxylation of l-o. to putrescine and CO2; first step in polyamine biosynthesis.
o. transaminase o. delta-aminotransferase
o. transcarbamoylase o. carbamoyltransferase



Copyright© 1995 Williams & Wilkins. All rights reserved.

ornithinemia ornithinemia (or´ni-thi-ne´me-a)
A toxic condition occasionally producing localized cerebral swelling, caused by abnormal amounts of ammonia in the blood. [ornithine + G. haima, blood]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ornithinuria ornithinuria (or´ni-thi-nu´re-a)
Excretion of excessive amounts of ornithine in the urine.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ornithodoros Ornithodoros (or-ni-thod´o-rus)
A genus of soft ticks (family Argasidae) several species of which are vectors of pathogens of various relapsing fevers. They are characterized by a capitulum hidden below the hood and by disks and mamillae of the integument that are continuous from dorsal to ventral surfaces in a variety of patterns. [G. ornis (ornith-), bird, + doros, a leather bag]
O. coria´ceus a species common in the mountainous coastal areas of California; adults readily attack deer, cattle, and humans, and have an irritating, painful, sometimes toxic bite. Transmits epizootic bovine abortion to cattle.pajaroello;
O. errat´icus a species the small variety of which is the vector of Borrelia crocidurae in Africa, the Near East, and central Asia; the large variety is the vector of B. hispanica in the Spanish peninsula and adjacent north Africa.
O. herm´si a species that is a rodent parasite and vector of relapsing fever spirochetes, such as Borrelia hermsii, in the western U.S. and Canada.
O. lahoren´sis a species that possibly transmits Borrelia persica, the agent of Persian relapsing fever.
O. mouba´ta complex a group of four species in Africa; the taxonomy and ecology of this complex is of great significance because its members are vectors of relapsing fever spirochetes; members of the complex include O. moubata (various hosts), O. compactus (tortoises), O. apertus (porcupines), and O. porcinus (warthogs); a domestic subspecies of O. porcinus, in turn, forms three strains that feed chiefly on humans, fowl, and swine.
O. pappil´ipes the "Persian bug," a species found in the former USSR and the Near East that transmits Borrelia persica, the pathogen in Iran of Persian relapsing fever.
O. par´keri a species found in the western U.S. and a vector of Borrelia parkeri.
O. ru´dis a species that is an important vector of relapsing fever spirochetes in Central and South America; possibly another complex similar to the O. moubata complex.
O. savi´gni a species transmitting Borrelia, an agent of relapsing fever of eastern Africa, southern Egypt, Ethiopia, and southwestern Asia.
O. talajé a species found in Mexico and in Central and South America, where it feeds on wild rodents, domestic animals, and humans; it delivers a painful, irritating bite and is a vector of Borrelia mazzottii, a cause of relapsing fever.
O. tholoza´ni a species transmitting Borrelia persica, an agent of relapsing fever in the Middle East and central Asia.
O. turica´ta a species that readily attacks man and other animals in the southern portion of the U.S. and Mexico; it is a vector of Borrelia turicatae, an agent of relapsing fever; the bite is painful and irritating.
O. venezuelen´sis a species that is the vector of Borrelia venezuelensis, agent of relapsing fever in Colombia, Venezuela, and mountainous parts of South America.
O. verruco´sus vector of Borrelia caucasica.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ornithonyssus Ornithonyssus (or-ni-thon´i-sus)
A genus of bird and rodent mites; species include O. bacoti, the tropical rat mite, a possible vector of murine typhus and a cause of human dermatitis; O. bursa, the tropical fowl mite; and O. sylviarum, the northern fowl mite. [G. ornis (ornith-), bird, + nyssus, to prick]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ornithosis ornithosis (or-ni-tho´sis)
Originally, a disease in nonpsittacine birds (domestic fowls, ducks, pigeons, turkeys, and many wild birds) caused by Chlamydia psittaci; now, generally referred to as psittacosis. [G. ornis (ornith-), bird, + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oro Oro
Symbol for orotic acid or orotate.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oro- oro-
1. The mouth. [L. os, oris, mouth] 2. Obsolete alternative spelling is orrho-. See sero-. [G. orrhos, whey, serum]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orodigitofacial orodigitofacial (or´o-dij´i-to-fa´shal)
Relating to the mouth, fingers, and face.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orofacial orofacial (or-o-fa´shal)
Relating to the mouth and face.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orolingual orolingual (or-o-ling´gwal)
Relating to the mouth and tongue.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oronasal oronasal (or-o-na´sal)
Relating to the mouth and nose.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oropharyngeal oropharyngeal (or-o-fa-rin´je-al)
Relating to the oropharynx.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oropharynx oropharynx (or´o-far´ingks)
The portion of the pharynx that lies posterior to the mouth; it is continuous above with the nasopharynx via the pharyngeal isthmus and below with the laryngopharynx.pars oralis pharyngis [NA], oral part of pharynx, oral pharynx; [L. os (or-), mouth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orosomucoid orosomucoid (or´o-so-myu´koyd)
a1-acid glycoprotein;a subgroup of the a1-globulin fraction of blood; increased plasma levels are associated with inflammation.a1-acid glycoprotein, acid seromucoid;



Copyright© 1995 Williams & Wilkins. All rights reserved.

orotate (Oro) orotate (Oro) (or´o-tat)
A salt or ester of orotic acid.
o. phosphoribosyltransferase a phosphoribosyltransferase synthesizing orotidylate and pyrophosphate from orotate and 5-phospho-a-d-ribosyl-1-pyrophosphate; this enzyme is a part of pyrimidine biosynthesis; a deficiency of this enzyme is associated with orotic aciduria type I. Cf. uridylic acid synthase. OMP pyrophosphorylase, orotidylic acid phosphorylase, orotidylic acid pyrophosphorylase;



Copyright© 1995 Williams & Wilkins. All rights reserved.

orotic acid (Oro) orotic acid (Oro) (or-ot´ik)
6-Carboxyuracil; uracil-6-carboxylic acid;an important intermediate in the formation of the pyrimidine nucleotides; elevated in certain inherited defects of pyrimidine biosynthesis.uracil-6-carboxylic acid;



Copyright© 1995 Williams & Wilkins. All rights reserved.

orotic aciduria orotic aciduria [MIM*258900]
A rare disorder of pyrimidine metabolism characterized by hypochromic anemia with megaloblastic changes in bone marrow, leukopenia, retarded growth, and urinary excretion of orotic acid; autosomal recessive inheritance. [orotic acid + G. ouron, urine]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orotidine (O, Ord) orotidine (O, Ord) (o-rot´i-den)
orotic acid-3-beta-d-ribonucleoside; uridine-6-carboxylic acid;elevated in cases of orotidinuria.1-ribosylorotate;
o. 5´-monophosphate (OMP) orotidylic acid



Copyright© 1995 Williams & Wilkins. All rights reserved.

orotidinuria orotidinuria (o-rot´i-den-yu´re-a)
Elevated levels of orotidine in the urine; has been observed in defects in and inhibition of orotidylic acid decarboxylase.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orotidylate (OMP) orotidylate (OMP) (o-rot-i-dil´at)
A salt or ester of orotidylic acid.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orotidylic acid (OMP) orotidylic acid (OMP) (o-rot-i-dil´ik)
Orotidine 5´-monophosphate;an intermediate in the biosynthesis of the pyrimidine nucleosides (cytidine and uridine) that are found in nucleic acids.orotidine 5´-monophosphate;
o.a. decarboxylase an enzyme that catalyzes the conversion of OMP to UMP and CO2; a defect or inhibition of this enzyme will result in orotic aciduria and orotidinuria; this enzyme is a part of pyrimidine biosynthesis. Cf. uridylic acid synthase. OMP decarboxylase;
o.a. phosphorylase orotate phosphoribosyltransferase
o.a. pyrophosphorylase orotate phosphoribosyltransferase



Copyright© 1995 Williams & Wilkins. All rights reserved.

orphan orphan (or´fan)
See orphan products, under product. [G. orphanos]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orphenadrine citrate orphenadrine citrate (or-fen´a-dren)
An antihistaminic that also has the same action and use as orphenadrine hydrochloride.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orphenadrine hydrochloride orphenadrine hydrochloride
N,N-Dimethyl-2(o-methyl-a-phenylbenzoyloxy)ethylamine hydrochloride; the o-methyl analogue of diphenhydramine hydrochloride;it reduces spasm of voluntary muscles, probably by action on the cerebral motor areas; used in the symptomatic treatment of paralysis agitans and drug-induced parkinsonism.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orrho- orrho-
OBSOLETE serum. See sero-. [G. orrhos, oros, whey, serum]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orris orris (or´is)
iris



Copyright© 1995 Williams & Wilkins. All rights reserved.

orseillin BB orseillin BB (or-sIl-in) [C.I. 26670]
A red diazo acid dye, C24H18N4O7S2Na2, used as a fungal and bacterial stain.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Orsi Orsi
Francesco, Italian physician, 1828-1890. See O.-Grocco method.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Orth Orth
Johannes J., German pathologist, 1847-1923. See O.'s fixative, stain.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orth- orth-
See ortho-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthergasia orthergasia (orth-er-ga´ze-a)
Rarely used term for normal intellectual and emotional adjustment. [G. orthos, straight, correct, + ergasia, work]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthesis orthesis (or-the´sis)
Rarely used term for an orthopedic brace, splint, or appliance. [ortho- + -esis, process]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthetics orthetics (or-thet´iks)
orthotics



Copyright© 1995 Williams & Wilkins. All rights reserved.

ortho- ortho- , orth-
1. Prefix denoting straight, normal, in proper order. 2. (o-) In chemistry, italicized prefix denoting that a compound has two substitutions on adjacent carbon atoms in a benzene ring. For terms beginning ortho- or o-, see the specific name. [Gr. orthos correct]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthoacid orthoacid (or´tho-as´id)
An acid in which the number of hydroxyl groups equals the valence of the acid-forming element; e.g., C(OH)4, orthocarbonic acid. When there is no such acid, the one that most nearly approaches this condition is sometimes called an o.; e.g., OP(OH)3, orthophosphoric acid.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthoarteriotony orthoarteriotony (or´tho-ar-ter-e-ot´o-ne)
Normal blood pressure. [ortho- + G. arteria, artery, + tonos, tension]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthobiosis orthobiosis (or´tho-bI-o´sis)
Rarely used term for correct living, both hygienically and morally. [ortho- + G. biosis, life]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthocaine orthocaine (or´tho-kan)
The methyl ester of 3-amino-4-hydroxybenzoic acid; a surface anesthetic agent usually used in dusting powder form.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthocephalic orthocephalic (or´tho-se-fal´ik)
Having a head well proportioned to height; denoting a skull with a vertical index between 70 and 75. See also metriocephalic.orthocephalous; [ortho- + G. kephale, head]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthocephalous orthocephalous (or-tho-sef´a-lus)
orthocephalic



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthochorea orthochorea (or´tho-kor-e´a)
A form of chorea in which the spasms occur only or chiefly when the patient is in the erect posture.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthochromatic orthochromatic (or´tho-kro-mat´ic)
Denoting any tissue or cell that stains the color of the dye used, i.e., the same color as the dye solution with which it is stained.euchromatic (1), orthochromophil, orthochromophile; [ortho- + G. chroma, color]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthochromophil orthochromophil , orthochromophile (or-tho-kro´mo-fil, -fIl)
orthochromatic [ortho- + G. chroma, color, + philos, fond]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthocrasia orthocrasia (or-tho-kra´se-a)
Obsolete term for condition in which there is a normal reaction to drugs, articles of diet, etc. [ortho- + G. krasis, a mixing, temperament]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthocytosis orthocytosis (or´tho-sI-to´sis)
A condition in which all of the cellular elements in the circulating blood are mature forms, irrespective of the proportions of various types and total numbers. [ortho- + G. kytos, cell, + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthodentin orthodentin (or-tho-den´tin)
Straight tubed dentin as seen in the teeth of mammals.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthodeoxia orthodeoxia
Fall in arterial blood oxygen upon assuming the upright posture. Usually due to right-to-left cardiac or vascular shunting with a posturally induced fall in left sided pressure permitting a corresponding gradient across the shunt.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthodigita orthodigita (or-tho-dij´I-tah)
Correction of malformations of fingers or toes. [ortho- + L. digitus, finger or toe]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthodontia orthodontia (or-tho-don´she-a)
orthodontics



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthodontics orthodontics (or-tho-don´tiks)
That branch of dentistry concerned with the correction and prevention of irregularities and malocclusion of the teeth.dental orthopedics, orthodontia; [ortho- + G. odous, tooth]
surgical o. the correction of occlusal abnormalities by the surgical repositioning of segments of the mandible or maxillae containing one to several teeth; or the bodily repositioning of entire jaws to improve function and esthetics.orthognathic surgery;



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthodontist orthodontist
A dental specialist who practices orthodontics.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthodromic orthodromic (or-tho-dro´mik)
Denoting the propagation of an impulse along an axon in the normal direction. Cf. antidromic. dromic; [ortho- + G. dromos, course]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthogenesis orthogenesis (or-tho-jen´e-sis)
The doctrine that evolution is governed by intrinsic factors and occurs in predictable directions. [ortho- + G. genesis, origin]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthogenic orthogenic (or-tho-jen´ik)
Relating to orthogenesis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthogenics orthogenics (or-tho-jen´iks)
eugenics



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthognathia orthognathia (or-tho-nath´e-a)
The study of the causes and treatment of conditions related to malposition of the bones of the jaws. [ortho- + G. gnathos, jaw]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthognathic orthognathic , orthognathous (or-tho-nath´ik, or-thog´nathus)
1. Relating to orthognathia. 2. Having a face without projecting jaw, one with a gnathic index below 98. [ortho- + G. gnathos, jaw]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthograde orthograde (or´tho-grad)
Walking or standing erect; denoting the posture of man; opposed to pronograde. [ortho- + L. gradior, pp. gressus, to walk]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthokeratology orthokeratology (or´tho-ker-a-tol´o-je)
A method of molding the cornea with contact lenses to improve unaided vision. [ortho- + G. keras, horn (cornea), + logos, science]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthokeratosis orthokeratosis (or´tho-ker-a-to´sis)
Formation of an anuclear keratin layer, as in the normal epidermis. [ortho- + G. keras, horn, + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthokinetics orthokinetics (or-tho-ki-net´iks)
A method advocated for the treatment of hypertrophic osteoarthritis in which an attempt is made to change muscular action from one group of muscles to another set of muscles to protect the diseased joint. [ortho- + G. kinetikos, movable, fr. kineo, to move]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthomechanical orthomechanical (or-tho-me-kan´i-kal)
Pertaining to braces, prostheses, orthotic devices, and appliances. [ortho- + mechanical]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthomechanotherapy orthomechanotherapy (or´tho-me-kan-o-thar´a-pe)
Treatment with braces, prostheses, orthotic devices, or appliances. [ortho- + G. mechane, machine, + therapeia, medical treatment]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthomelic orthomelic (or-tho-me´lik)
Correcting malformations of arms or legs. [ortho- + G. melos, limb]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthometer orthometer (or-thom´e-ter)
exophthalmometer [ortho- + G. metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthomolecular orthomolecular (or´tho-mo-lek´yu-lar)
L.C. Pauling's term denoting a therapeutic approach designed to provide an optimum molecular environment for body functions, with particular reference to the optimum concentrations of substances normally present in the human body, whether formed endogenously or ingested.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Orthomyxoviridae Orthomyxoviridae (or´tho-mik-so-vir´i-de)
The family of viruses that comprises the three groups of influenza viruses, types A, B, and C. Virions are roughly spherical or filamentous, the former (the more common form) are 80 to 120 nm in diameter and ether-sensitive; envelopes are studded with surface projections; nucleocapsids are of helical symmetry, 6 to 9 nm in diameter, and contain single-stranded, segmented RNA. The nucleoprotein antigen of each type of virus is common to all strains of the type but distinct from those of the other two types; the mosaic of surface antigens varies from strain to strain. Nucleocapsids seem to be formed in the nuclei of infected cells, hemagglutinin and neuraminidase in the cytoplasm; virus maturation occurs during budding of the cell membrane. The only recognized genus is Influenzavirus, which comprises the strains of virus types A and B, both of which are subject to mutation resulting in epidemics. Influenza virus type C differs from types A and B somewhat (e.g., the "receptor-destroying enzyme" seems not to be a neuraminidase) and probably belongs to a separate genus. See also Influenzavirus.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthopaedic orthopaedic , orthopedic (or-tho-pe´dik)
Relating to orthopaedics.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthopaedics orthopaedics , orthopedics (or-tho-pe´diks)
The medical specialty concerned with the preservation, restoration, and development of form and function of the musculoskeletal system, extremities, spine, and associated structures by medical, surgical, and physical methods.orthopedics; [ortho- + G. pais (paid-), child]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthopaedist orthopaedist , orthopedist (or-tho-pe´dist)
One who practices orthopaedics.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthopedics orthopedics (or-tho-pe´diks)
orthopaedics
dental o. orthodontics
functional jaw o. utilization of muscle forces to effect changes in jaw position and tooth alignment by removable appliances.functional orthodontic therapy;



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthopercussion orthopercussion (or´tho-per-kush´un)
Very light percussion of the chest, made in a sagittal direction (i.e., anteroposteriorly, and not perpendicularly to the wall of the chest); used to determine the size of the heart, the faint percussion sound disappearing when the heart is reached even though that may be overlapped by a layer of the lung.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthophoria orthophoria (or-tho-for´e-a)
Absence of heterophoria; the condition of binocular fixation in which the lines of sight meet at a distant or near point of reference in the absence of a fusion stimulus. [ortho- + G. phora, motion]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthophoric orthophoric (or-tho-for´ik)
Pertaining to orthophoria.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthophosphate orthophosphate (or-tho-fos´fat)
A salt or ester of orthophosphoric acid.
inorganic o. (Pi, P1) any ion or salt form of phosphoric acid.inorganic phosphate;



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthophosphoric acid orthophosphoric acid (or´tho-fos-for´ik)
Phosphoric acid, O=P(OH)3, distinguished by ortho- from meta- and pyrophosphoric acids, (HPO3)n and OP(OH2)OP(OH)2O, respectively, which are anhydrides of H3PO4; the ultimate anhydride is phosphorus pentoxide, P2O5.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthophrenia orthophrenia (or-tho-fre´ne-a)
1. Rarely used term for soundness of mind. 2. Rarely used term for a condition of normal interpersonal relationships. [ortho- + G. phren, mind]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthopnea orthopnea (or-thop-ne´a, or-thop´ne-a)
Discomfort in breathing which is brought on or aggravated by lying flat. Cf. platypnea. [ortho- + G. pnoe, a breathing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthopneic orthopneic (or´thop-ne´ik)
Relating to or characterized by orthopnea.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Orthopoxvirus Orthopoxvirus (or-tho-poks´vI-rus)
The genus of the family Poxviridae which comprises the viruses of alastrim, vaccinia, variola, cowpox, ectromelia, monkeypox, and rabbitpox.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthoprosthesis orthoprosthesis (or´tho-pros´the-sis, -pros-the´sis)
An appliance used in the management of prosthetic problems related to alignment of teeth.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthopsychiatry orthopsychiatry (or´tho-sI-kI´a-tre)
A cross-disciplinary science combining child psychiatry, developmental psychology, pediatrics, and family care devoted to the discovery, prevention, and treatment of mental and psychological disorders in children and adolescents.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Orthoptera Orthoptera (or-thop´ter-a)
A large order of hemimetabolous insects that includes the locusts, grasshoppers, mantids, walking sticks, and related forms. [ortho- + G. pteron, a wing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthoptic orthoptic (or-thop´tik)
Relating to orthoptics.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthoptics orthoptics (or-thop´tiks)
The study and treatment of defective binocular vision, of defects in the action of the ocular muscles, or of faulty visual habits. [ortho- straightened + G. optikos, sight]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthoptist orthoptist (or-thop´tist)
One skilled in orthoptics.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthoscope orthoscope (or´tho-skop)
1. An instrument by means of which one is able to draw the outlines of the various normas of the skull. [ortho- + G. skopeo, to view]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthosis orthosis, pl. orthoses (or-tho´sis, -sez)
An external orthopaedic appliance, as a brace or splint, that prevents or assists movement of the spine or the limbs. [G. orthosis, a making straight]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthostatic orthostatic (or-tho-stat´ik)
Relating to an erect posture or position.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthostereoscope orthostereoscope (or´tho-ster´e-o-skop)
A rarely used instrument for viewing stereoscopic radiographs.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthosympathetic orthosympathetic (or´tho-sim-pa-thet´ik)
Referring to the sympathetic component of the autonomic nervous system, as distinguished from parasympathetic. See autonomic nervous system.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthothanasia orthothanasia (or´tho-tha-na´ze-a)
1. A normal or natural manner of death and dying. 2. Sometimes used to denote the deliberate stopping of artificial or heroic means of maintaining life. [ortho- + G. thanatos, death]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthotics orthotics (or-thot´iks)
The science concerned with the making and fitting of orthopaedic appliances.orthetics;



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthotist orthotist (or´tho´tist)
A maker and fitter of orthopaedic appliances.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthotolidine orthotolidine (or-tho-to´li-den)
o-Tolidine; 3,3´-dimethylbenzidine;in the presence of peroxidase, o. (like benzidine) is oxidized to a blue color; since hemoglobin behaves like a peroxidase, o. has been used as an in vitro aid for the detection of occult blood in feces.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthotonos orthotonos , orthotonus (or-thot´o-nos, -o-nus)
A form of tetanic spasm in which the neck, limbs, and body are held fixed in a straight line. [ortho- + G. tonos, tension]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthotopic orthotopic (or-tho-top´ik)
In the normal or usual position. [ortho- + G. topos, place]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthotropic orthotropic (or-tho-trop´ik)
Extending or growing in a straight, especially a vertical, direction. [ortho- + G. trope, a turn]



Copyright© 1995 Williams & Wilkins. All rights reserved.

orthovoltage orthovoltage (or-tho-vol´tij)
In radiation therapy, a vague term for voltage between 400 and 600 kv.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Orton Orton
S.T., U.S. neurologist, 1879-1975. See Wolf-O. bodies, under body.



Copyright© 1995 Williams & Wilkins. All rights reserved.

orycenin orycenin (or-e-sen´in)
A glutelin in rice. [G. oryza, rice, + -in]



Copyright© 1995 Williams & Wilkins. All rights reserved.

O.S. O.S.
Abbreviation for L. oculus sinister, left eye.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Os Os
Symbol for osmium.



Copyright© 1995 Williams & Wilkins. All rights reserved.

os os, gen. o´ris, pl. ora
1. [NA] The mouth. 2. Term applied sometimes to an opening into a hollow organ or canal, especially one with thick or fleshy edges. [L. mouth]
external o. of uterus the vaginal opening of the uterus.ostium uteri [NA], mouth of the womb, opening of uterus, orificium externum uteri, o. uteri externum, ostium uteri externum;
incompetent cervical o. a defect in the strength of the internal o. allowing premature dilation of the cervix.
Scanzoni's second o. pathologic retraction ring
o. u´teri exter´num external o. of uterus
o. u´teri inter´num isthmus of uterus



Copyright© 1995 Williams & Wilkins. All rights reserved.

os os, gen. ossis, pl. ossa (os, os´is, os´a) [NA]
boneFor histological description, see bone [L. bone]
o. acromia´le an acromion that is joined to the scapular spine by fibrous rather than by bony union.
o. basila´re basilar bone
o. bre´ve [NA] short bone
o. cal´cis calcaneus (1)
o. capita´tum [NA] capitate (1)
os´sa car´pi [NA] carpal bones, under bone
o. centra´le [NA] a small bone occasionally found at the dorsal aspect of the wrist between the scaphoid, capitate, and trapezoid; it is developed as an independent cartilage in early fetal life but usually becomes fused with the scaphoid; it occurs normally in most monkeys.central bone;
o. centra´le tar´si navicular bone
o. clitor´idis a small bone located in the clitoris of many carnivorous mammals. It is homologous with the o. penis of many male mammals.
o. coc´cygis [NA] coccyx
o. costa´le [NA] Rib
o. cox´ae [NA] hip bone
ossa cra´nii [NA] bones of skull, under bone
o. cuboi´deum [NA] cuboid bone
o. cuneifor´me interme´dium [NA] intermediate cuneiform bone
o. cuneifor´me latera´le [NA] lateral cuneiform bone
o. cuneifor´me media´le [NA] medial cuneiform bone
os´sa digito´rum [NA] bones of digits, under bone See also phalanx (1).
o. ethmoida´le [NA] ethmoid bone
os´sa facie´i [NA] facial bones, under bone
o. fem´oris [NA] femur
o. fronta´le [NA] frontal bone
o. hama´tum [NA] hamate bone
o. hyoi´deum [NA] hyoid bone See also hyoid apparatus.
o. iliacum * official alternate term for ilium
o. il´ium [NA] ilium
o. in´cae o. interparietale
o. incisi´vum [NA] the anterior and inner portion of the maxilla, which in the fetus and sometimes in the adult is a separate bone; the incisive suture runs from the incisive canal between the lateral incisor and the canine tooth; according to K. Albrecht, the o. incisivum is further divided by a suture between the two incisor teeth on each side into two bones, the endognathion and the mesognathion.incisive bone, intermaxilla, intermaxillary bone, o. intermaxillare, o. premaxillare, premaxilla (1), premaxillary bone;
o. innomina´tum hip bone
o. intermaxilla´re o. incisivum
o. interme´dium lunate bone
o. intermetatar´seum a supernumerary bone at the base of the first metatarsal, or between the first and second metatarsal bones, usually fused with one or the other or with the medial cuneiform bone.intermetatarseum;
o. interparieta´le [NA] the upper part of the squama of the occipital bone, developed in membrane instead of in cartilage as is the rest of the occipital, and occasionally (especially in ancient Peruvian skulls) existing as a separate bone, separated from the remainder of the occipital by the sutura mendosa.incarial bone, interparietal bone, o. incae;
o. irregula´re [NA] irregular bone
o. is´chii [NA] ischium
o. japon´icum a bipartite or tripartite zygomatic bone, found with greater frequency in the Japanese than in other races.
o. lacrima´le [NA] lacrimal bone
o. lon´gum [NA] long bone
o. luna´tum [NA] lunate bone
o. mag´num capitate (1)
o. mala´re zygomatic bone
os´sa mem´bri inferio´ris [NA] bones of lower limb, under bone
os´sa mem´bri superio´ris [NA] bones of upper limb, under bone
o. metacarpa´le, pl. os´sa metacarpa´lia [NA] metacarpal bone
o. metatarsa´le, pl. os´sa metatarsa´lia [NA] metatarsal bone
o. multan´gulum ma´jus trapezium
o. multan´gulum mi´nus trapezoid bone
o. nasa´le [NA] nasal bone
o. navicula´re [NA] navicular bone
o. navicula´re ma´nus scaphoid bone
o. occipita´le [NA] occipital bone
o. odontoi´deum the dens of the axis when anomalously not fused with the body of the axis.
o. orbicula´re lenticular process of incus
o. palati´num [NA] palatine bone
o. parieta´le [NA] parietal bone
o. pe´nis a bone of variable size and shape, located in the glans penis or glans clitoridis of all animals, except man, ungulates, elephants, whales, and a few others; it is particularly well developed in carnivora, and in the dog may reach a length of more than 10 cm; its size and shape are often a characteristic of a species.baculum, penis bone;
o. pisifor´me [NA] pisiform bone
o. pla´num [NA] flat bone
o. pneumat´icum [NA] pneumatic bone
o. premaxilla´re o. incisivum
o. pterygoi´deum pterygoid process
o. pu´bis [NA] mons pubis
o. pyramida´le triquetral bone
o. sa´crum [NA] sacrum
o. scaphoi´deum [NA] scaphoid bone
o. sesamoi´deum, pl. os´sa sesamoi´dea [NA] sesamoid bone
o. sphenoida´le [NA] sphenoid bone
o. subtibia´le an inconstant bone found very rarely in the distal articular end of the tibia.
o. suprasterna´le, pl. os´sa suprasterna´lia [NA] one of the small ossicles occasionally found in the ligaments of the sternoclavicular articulation.Breschet's bones, episternal bone, suprasternal bone;
os´sa sutura´rum [NA] sutural bones, under bone
o. syl´vii lenticular process of incus
os´sa tar´si [NA] tarsal bones, under bone
o. tempora´le [NA] temporal bone
o. tibia´le poste´rius , o. tibia´le posti´cum a sesamoid bone in the tendon of the tibialis posterior muscle, occasionally fused with the tuberosity of the navicular.tibiale posticum;
o. trape´zium [NA] trapezium
o. trapezoi´deum [NA] trapezoid bone
o. triangula´re 1. o. trigonum 2. triquetral bone
o. tribasila´re the single bone resulting from the fusion in infancy of the occipital and temporal bones at the base of the cranial cavity.
o. trigo´num [NA] an independent ossicle sometimes present in the tarsus; usually it forms part of the talus, constituting the lateral tubercle of the posterior process.o. triangulare (1), triangular bone;
o. trique´trum [NA] triquetral bone
o. un´guis lacrimal bone
o. vesalia´num the tuberosity of the fifth metatarsal bone sometimes existing as a separate bone.vesalianum, Vesalius' bone;
o. zygomat´icum [NA] zygomatic bone



Copyright© 1995 Williams & Wilkins. All rights reserved.

osazone osazone (o´sa-zon)
The compound formed by certain sugars (e.g., glucose, galactose, fructose) with excess hydrazines, possessing two hydrazones on carbons 1 and 2 instead of only one at C-1, as in the ordinary hydrazone; o.'s formed with phenylhydrazine (phenylosazones) are used to characterize and identify certain sugars.dihydrazone;



Copyright© 1995 Williams & Wilkins. All rights reserved.

osche- osche- , oscheo-
The scrotum. [G. osche]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscheal oscheal (os´ke-al)
scrotal



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscheitis oscheitis (os-ke-I´tis)
Inflammation of the scrotum. [osche- + G. -itis, inflammation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oschelephantiasis oschelephantiasis (osk´el-e-fan-tI´a-sis)
An enlargement or elephantiasis of the scrotum. [osche- + elephantiasis]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscheohydrocele oscheohydrocele (os-ke-o-hI´dro-sel)
Scrotal hydrocele. [oscheo- + G. hydor, water, + kele, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscheoplasty oscheoplasty (os´ke-o-plas-te)
scrotoplasty [oscheo- + plastos, formed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscillation oscillation (os-i-la´shun)
1. A to-and-fro movement. 2. A stage in the vascular changes in inflammation in which the accumulation of leukocytes in the small vessels arrests the passage of blood and there is simply a to-and-fro movement at each cardiac contraction. [L. oscillatio, fr. oscillo, to swing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscillator oscillator (os´si-la-ter)
1. An apparatus somewhat like a vibrator, used to give a form of mechanical massage. 2. An electric circuit designed to generate alternating current at a particular frequency. 3. Any device that produces oscillation.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscillograph oscillograph (o-sil´o-graf)
An instrument that records oscillations, usually electrical.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscillography oscillography (os-i-log´ra-fe)
The study of the records made by an oscillograph.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscillometer oscillometer (os-i-lom´e-ter)
An apparatus for measuring oscillations of any kind, especially those of the bloodstream in sphygmometry. See also sphygmo-oscillometer. [L. oscillo, to swing, + G. metron, measure]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscillometric oscillometric (os´i-lo-met´rik)
Relating to the oscillometer or the records made by its use.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscillometry oscillometry (os-i-lom´e-tre)
The measurement of oscillations of any kind with an oscillometer.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscillopsia oscillopsia (os-i-lop´se-a)
The subjective sensation of oscillation of objects viewed.oscillating vision; [L. oscillo, to swing, + G. opsis, vision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscilloscope oscilloscope (o-sil´o-skop)
An oscillograph in which the record of oscillations is continuously visible.
cathode ray o. (CRO) the common form of o., in which a varying electrical signal (y) vertically deflects an electron beam impinging on a fluorescent screen, while some other function (x or time) deflects the beam horizontally; the result is a visual graph of y plotted against x or time with negligible distortion by inertia.
storage o. a cathode ray o. in which the visual record of oscillations persists on the fluorescent screen until erased electrically.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscitate oscitate (os´i-tat)
To yawn; to gape. [L. oscito, fr. os, mouth, + cieo, to put in motion]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oscitation oscitation (os´i-ta´shun)
yawning [L. oscitatio]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osculum osculum, pl. oscula (os´kyu-lum, -la)
A pore or minute opening. [L. dim. of os, mouth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

-ose -ose
1. In chemistry, a terminator usually indicating a carbohydrate. 2. Suffix appended to some Latin roots, with significance of the more common -ous (2) . [L. -osus, full of, abounding] 3. Full of, having much of.



Copyright© 1995 Williams & Wilkins. All rights reserved.

-oses -oses
Plural of -osis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Osgood Osgood
Robert B., U.S. orthopedic surgeon, 1873-1956. See O.-Schlatter disease.



Copyright© 1995 Williams & Wilkins. All rights reserved.

OSHA OSHA
Abbreviation for Occupational Safety and Health Administration of the U.S. Department of Labor, responsible for establishing and enforcing safety and health standards in the workplace.



Copyright© 1995 Williams & Wilkins. All rights reserved.

-osis -osis, pl. -oses
Suffix, properly added only to words formed from G. roots, meaning a process, condition, or state, usually abnormal or diseased. It denotes primarily any production or increase, physiologic or pathologic, and secondarily an invasion, and increase within the organism, of parasites; in the latter sense, it is similar to and often interchangeable with G. -iasis, as seen in trichinosis, trichiniasis. [G.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Osler Osler
Sir William, Canadian physician in U.S. and England, 1849-1919. See O.'s disease; O. node; O.'s sign; Rendu-O.-Weber syndrome.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmate osmate (os´mat)
A salt of osmic acid.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmatic osmatic (oz-mat´ik)
olfactory [G. osme, smell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmesis osmesis (oz-me´sis)
olfaction [G. osmesis, smelling]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmic acid osmic acid (oz´mik)
OsO4;a volatile caustic and strong oxidizing agent; colorless crystals, poorly soluble in water, but soluble in organic solvents; the aqueous solution is a fat and myelin stain and a general fixative for electron microscopy.osmium tetroxide;



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmicate osmicate (oz´mi-kat)
To stain or fix with osmic acid.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmication osmication , osmification (os´mi-ka´shun, os´mi-fi-ka´shun)
The fixation of tissue with an osmic acid solution; also serves as a stain for both light and electron microscopy.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmics osmics (oz´miks)
The science of olfaction. [G. osme, smell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmidrosis osmidrosis (oz-mi-dro´sis)
bromidrosis [G. osme, smell, + hidros, sweat]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmiophilic osmiophilic (oz´mi-o-fil´ik)
Readily stained with osmic acid. [osmium + G. phileo, to love]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmiophobic osmiophobic (oz´mi-o-fo´bik)
Not readily stained with osmic acid. [osmium + G. phobos, fear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmium (Os) osmium (Os) (oz´me-um)
A metallic element of the platinum group, atomic no. 76, atomic wt. 190.2. [G. osme, smell, because of the strong odor of the tetroxide]
o. tetroxide osmic acid



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmo- osmo-
1. Osmosis. [G. osmos, impulsion] 2. Smell, odor. [G. osme]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmoceptor osmoceptor (os-mo-sep´ter, tor)
osmoreceptor



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmodysphoria osmodysphoria (oz´mo-dis-for´e-a)
An abnormal dislike of certain odors. [G. osme, smell, + dys-, bad, + phora, a carrying]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmogram osmogram (oz´mo-gram)
electro-olfactogram [G. osme, smell, + gramma, a drawing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmolality osmolality (os-mo-lal´i-te)
The concentration of a solution expressed in osmoles of solute particles per kilogram of soluent.
calculated serum osmolality the calculation of serum osmolality from serum sodium, glucose, and urea nitrogen values by a variety of formulae, the most common of which is: 1.86 x [Na30] + glucose(mg/dl)/18 + BUN(mg/dl)/2.8



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmolar osmolar (os-mo´lar)
osmotic



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmolarity osmolarity (os-mo-lar´i-te)
The osmotic concentration of a solution expressed as osmoles of solute per liter of solution.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmole osmole (os´mol)
The molecular weight of a solute, in grams, divided by the number of ions or particles into which it dissociates in solution.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmology osmology (os-mol´o-je)
1. The study of odors, their production, and their effects.osphresiology; 2. The study of osmosis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmometer osmometer (os-mom´e-ter)
An instrument for measuring osmolality by freezing point depression or vapor pressure elevation techniques.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmometry osmometry (os-mom´e-tre)
Measurement of osmolality by use of an osmometer.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmophil osmophil , osmophilic (os´mo-fil, -fil´ik)
Flourishing in a medium of high osmotic pressure. [osmo(sis) + G. phileo, to love]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmophobia osmophobia (oz-mo-fo´be-a)
olfactophobia [G. osme, smell, + phobia]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmophore osmophore (oz´mo-for)
The group of atoms in the molecule of a compound that is responsible for the compound's characteristic odor. [G. osme, smell, + phonos, bearing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmoreceptor osmoreceptor (os´mo-re-sep´ter, -tor)
1. A receptor in the central nervous system (probably the hypothalamus) that responds to changes in the osmotic pressure of the blood. [G. osmos, impulsion] 2. A receptor that receives olfactory stimuli. [G. osme, smell] osmoceptor;



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmoregulatory osmoregulatory (os-mo-reg´yu-la-tor-e)
Influencing the degree and rapidity of osmosis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmose osmose (os´mos)
To move through a membrane by osmosis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmosis osmosis (os-mo´sis)
The process by which solvent tends to move through a semipermeable membrane from a solution of lower to a solution of higher osmolal concentration of the solutes to which the membrane is relatively impermeable. [G. osmos, a thrusting, an impulsion]
reverse o. movement of solvent in the opposite direction from o., i.e., pressure filtration of solvent through a semipermeable membrane that will hold back the solutes; commonly replaced by filtration or ultrafiltration when speaking of capillary membranes, as in the renal glomerulus.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmosity osmosity (os-mos´i-te)
An indirect measure of the osmotic characteristics of a solution, in terms of a comparable sodium chloride solution, now rendered obsolete by the more precisely defined term osmolality.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmotherapy osmotherapy (os´mo-thar´a-pe)
Dehydration by means of intravenous injections of hypertonic solutions of sodium chloride, dextrose, urea, mannitol, or other osmotically active substances, or by oral administration of glycerine, isosorbide, glycine, etc.; used in the treatment of cerebral edema and increased intracranial pressure. [osmosis + therapy]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osmotic osmotic (os-mot´ik)
Relating to osmosis.osmolar;



Copyright© 1995 Williams & Wilkins. All rights reserved.

osphresio- osphresio-
Odor; sense of smell. [G. osphresis, smell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osphresiolagnia osphresiolagnia (os-fre´ze-o-lag´ne-a)
Sexual excitement produced by odors. [osphresio- + G. lagneia, lust]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osphresiologic osphresiologic (os-fre-ze-o-loj´ik)
Relating to osphresiology.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osphresiology osphresiology (os-fre´ze-ol´o-je)
osmology (1) [osphresio- + G. logos, study]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osphresiophilia osphresiophilia (os-fre´ze-o-fil´e-a)
An unusual interest in odors. [osphresio- + G. phileo, to love]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osphresiophobia osphresiophobia (os-fre´ze-o-fo´be-a)
olfactophobia [osphresio- + G. phobos, fear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osphresis osphresis (os-fre´sis)
olfaction [G. osphresis, smell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osphretic osphretic (os-fret´ik)
olfactory



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossa ossa (os´a)
Plural of L. os, bone. [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossein ossein , osseine (os´e-in)
collagen [L. os, bone]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osselet osselet (os´e-let)
A periostitis of the anterior margin of the third metacarpal bone or first phalanx near the fetlock, characterized first by a painful, soft swelling and later by exostosis; a cause of lameness in horses, particularly young race horses in training. [L. dim. of os, bone]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osseo- osseo-
Bony. See also ossi-, osteo-. [L. osseus]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osseocartilaginous osseocartilaginous (os´e-o-kar-ti-laj´i-nus)
Relating to, or composed of, both bone and cartilage.osteocartilaginous, osteochondrous;



Copyright© 1995 Williams & Wilkins. All rights reserved.

osseomucin osseomucin (os´e-o-myu´sin)
The ground substance of bony tissue.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osseomucoid osseomucoid (os´e-o-myu´koyd)
A mucoid derived from ossein.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osseous osseous (os´e-us)
Bony, of bone-like consistency or structure.osteal; [L. osseus]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossi- ossi-
Bone. See also osseo-, osteo-. [L. os]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossicle ossicle (os´i-kl)
A small bone; specifically, one of the bones of the tympanic cavity or middle ear.ossiculum [NA], bonelet; [L. ossiculum, dim. of os, bone]
Andernach's o.'s sutural bones, under bone
auditory o.'s the small bones of the middle ear; they are articulated to form a chain for the transmission of sound from the tympanic membrane to the oval window.ossicula auditus [NA], ear bones, ossicular chain;
Bertin's o.'s sphenoidal conchae, under concha
epactal o.'s sutural bones, under bone
Kerckring's o. Kerckring's center



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossicula ossicula (o-sik´yu-la)
Plural of ossiculum. [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossicular ossicular (o-sik´yu-lar)
Pertaining to an ossicle.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossiculectomy ossiculectomy (os´i-kyu-lek´to-me)
Removal of one or more of the ossicles of the middle ear. [L. ossiculum, ossicle, + G. ektome, excision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossiculotomy ossiculotomy (os´i-kyu-lot´o-me)
Division of one of the processes of the ossicles of the middle ear, or of a fibrous band causing ankylosis between any two ossicles. [L. ossiculum, ossicle, + G. tome, incision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossiculum ossiculum, pl. ossicula (o-sik´yu-lum, -la) [NA]
ossicle [L. dim. of os, bone]
ossicula audi´tus [NA] auditory ossicles, under ossicle
ossic´ula menta´lia small nodules of bone that appear at the symphysis menti shortly before birth and fuse with the mandible after birth.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossiferous ossiferous (o-sif´er-us)
Containing or producing bone. [ossi- + L. fero, to bear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossific ossific (o-sif´ik)
Relating to a change into, or formation of, bone.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossification ossification (os´i-fi-ka´shun)
1. The formation of bone. 2. A change into bone. [L. ossificatio, fr. os, bone, + facio, to make]
endochondral o. formation of osseous tissue by the replacement of calcified cartilage; long bones grow in length by endochondral o. at the epiphysial cartilage plate where osteoblasts form bone trabeculae on a framework of calcified cartilage.
intramembranous o. membranous o
membranous o. intramembranous o., development of osseous tissue within mesenchymal tissue without prior cartilage formation, such as occurs in the frontal and parietal bones.intramembranous o;
metaplastic o. the formation of irregular foci of bone (sometimes including bone marrow) in various soft structures, such as the muscles, lungs, brain, and other sites where osseous tissue is abnormal.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossiform ossiform (os´i-form)
osteoid (1) [ossi- + L. forma, form]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ossify ossify (os´i-fI)
To form bone or convert into bone. [ossi- + L. facio, to make]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ost- ost-
See osteo-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteal osteal (os´te-al)
osseous [G. osteon, bone]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostealgia ostealgia (os-te-al´je-a)
Pain in a bone.osteodynia; [osteo- + G. algos, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostealgic ostealgic (os-te-al´jik)
Relating to or marked by bone pain.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteanagenesis osteanagenesis (os´te-an-a-jen´e-sis)
osteoanagenesis



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteanaphysis osteanaphysis (os´te-a-naf´i-sis)
osteoanagenesis [osteo- + G. anaphysis, a growing again]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostectomy ostectomy (os-tek´to-me)
1. Surgical removal of bone. 2. In dentistry, resection of supporting osseous structure to eliminate periodontal pockets.osteoectomy; [osteo- + G. ektome, excision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostein ostein , osteine (os´te-in)
collagen [G. osteon, bone]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteitic osteitic (os-te-it´ik)
Relating to or affected by osteitis.ostitic;



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteitis osteitis (os-te-I´tis)
Inflammation of bone.ostitis; [osteo- + G. -itis, inflammation]
alveolar o. alveoalgia
caseous o. tuberculous caries in bone.
central o. 1. osteomyelitis 2. endosteitis
o. condensans ilii (con-den´sanz il´e-I) symmetric benign osteosclerosis of the portion of the iliac bones adjacent to the sacroiliac joints.
condensing o. sclerosing o
cortical o. periostitis with involvement of the superficial layer of bone.
o. defor´mans Paget's disease (1)
o. fibro´sa cir´cumscrip´ta monostotic fibrous dysplasia
o. fibro´sa cys´tica increased osteoclastic resorption of calcified bone with replacement by fibrous tissue, due to primary hyperparathyroidism or other causes of the rapid mobilization of mineral salts.parathyroid osteosis, Recklinghausen's disease of bone;
o. fibro´sa disseminat´a polyostotic fibrous dysplasia
focal condensing o. chronic focal sclerosing osteomyelitis
hematogenous o. any o. caused by infection carried in the bloodstream.
localized o. fibro´sa monostotic fibrous dysplasia
multifocal o. fibro´sa polyostotic fibrous dysplasia
o. pubis osteosclerosis of the pubic bone next to the symphysis, caused by trauma to that region, from pregnancy or instrumentation.
renal o. fibro´sa renal rickets
sclerosing o. fusiform thickening or increased density of bones, of unknown cause; it has been considered a form of chronic nonsuppurative osteomyelitis.condensing o., Garré's disease;
o. tuberculo´sa mul´tiplex cys´tica an o. of tuberculous origin, marked by numerous small cavities in the osseous substance.Jüngling's disease;



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostembryon ostembryon (os-tem´bre-on)
Archaic term for lithopedion. [osteo- + G. embryon, embryo]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostemia ostemia (os-te´me-a)
Congestion or hyperemia of a bone. [osteo- + G. haima, blood]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostempyesis ostempyesis (os´tem-pI-e´sis)
Suppuration in bone. [osteo- + G. empyesis, suppuration]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteo- osteo- , ost- , oste-
Bone. See also osseo-, ossi-. [G. osteon]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoanagenesis osteoanagenesis (os´te-o-an-a-jen´e-sis)
Regeneration of bone.osteanagenesis, osteanaphysis; [osteo- + G. ana, again, + genesis, generation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoarthritis osteoarthritis (os´te-o-ar-thrI´tis)
Arthritis characterized by erosion of articular cartilage, either primary or secondary to trauma or other conditions, which becomes soft, frayed, and thinned with eburnation of subchondral bone and outgrowths of marginal osteophytes; pain and loss of function result; mainly affects weight-bearing joints, is more common in older persons.degenerative arthritis, degenerative joint disease, hypertrophic arthritis, osteoarthrosis;
hyperplastic o. hypertrophic pulmonary osteoarthropathy



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoarthropathy osteoarthropathy (os´te-o-ar-throp´a-the)
A disorder affecting bones and joints. [osteo- + G. arthron, joint, + pathos, suffering]
hypertrophic pulmonary o. expansion of the distal ends, or the entire shafts, of the long bones, sometimes with erosions of the articular cartilages and thickening and villous proliferation of the synovial membranes, and frequently clubbing of fingers; the disorder occurs in chronic pulmonary disease, in heart disease, and occasionally in other acute and chronic disorders; also occurs in dogs as a result of Spirocerca lupi infection of the esophagus.Bamberger-Marie disease, Bamberger-Marie syndrome, hyperplastic osteoarthritis, pneumogenic o., pulmonary o;
idiopathic hypertrophic o. o. not secondary to pulmonary or other progressive lesions, which may occur alone (acropathy) or as part of the syndrome of pachydermoperiostosis.
pneumogenic o. hypertrophic pulmonary o
pulmonary o. hypertrophic pulmonary o



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoarthrosis osteoarthrosis (os´te-o-ar-thro´sis)
osteoarthritis [osteo- + G. arthron, joint, + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoblast osteoblast (os´te-o-blast)
A bone-forming cell that is derived from mesenchyme (fibroblast) and forms an osseous matrix in which it becomes enclosed as an osteocyte.osteoplast; [osteo- + G. blastos, germ]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoblastic osteoblastic (os´te-o-blas´tik)
Relating to the osteoblasts; describes any region of increased radiographic bone density, in particular, metastases that stimulate o. activity.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoblastoma osteoblastoma (os´te-o-blas-to´ma)
An uncommon benign tumor of osteoblasts with areas of osteoid and calcified tissue, occurring most frequently in the spine of a young person.giant osteoid osteoma;



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteocalcin osteocalcin
A protein found in bone and dentin; contains gamma-carboxyglutamyl residues; has a role in mineralization and calcium ion homeostasis.bone Gla protein;



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteocarcinoma osteocarcinoma (os´te-o-kar´si-no´ma)
Undesirable and obsolete nonspecific term for a metastasis of carcinoma in a bone, or a carcinoma that contains foci of osseous tissue (as a result of metaplasia).



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteocartilaginous osteocartilaginous (os´te-o-kar-ti-laj´i-nus)
osseocartilaginous



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteochondritis osteochondritis (os´te-o-kon-drI´tis)
Inflammation of a bone and its cartilage. [osteo- + G. chondros, cartilage, + -itis, inflammation]
o. defor´mans juveni´lis Legg-Calvé-Perthes disease
o. defor´mans juveni´lis dor´si Scheuermann's disease
o. dis´secans complete or incomplete separation of a portion of joint cartilage and underlying bone, usually involving the knee, associated with epiphyseal aseptic necrosis.
syphilitic o. inflammation of the epiphysial line associated with congenital syphilis.Wegner's disease;



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteochondrodysplasia osteochondrodysplasia
camptomelic syndrome



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteochondrodystrophia deformans osteochondrodystrophia deformans (os´te-o-kon´dro-dis-tro´fe-a de-for´manz)
chondro-osteodystrophy



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteochondrodystrophy osteochondrodystrophy (os´te-o-kon´dro-dis´tro-fe)
chondro-osteodystrophy



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteochondroma osteochondroma (os´te-o-kon-dro´ma)
A benign cartilaginous neoplasm that consists of a pedicle of normal bone (protruding from the cortex) covered with a rim of proliferating cartilage cells; may originate from any bone that is preformed in cartilage, but is most frequent near the ends of long bones, usually in patients who are 10 to 25 years of age; the lesion is frequently not noticed, unless it is traumatized or of large size; multiple o.'s are inherited and referred to as hereditary multiple exostoses.solitary osteocartilaginous exostosis; [osteo- + G. chondros, cartilage, + -oma, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteochondromatosis osteochondromatosis (os´te-o-kon-dro-ma-to´-sis)
hereditary multiple exostoses, under exostosis
synovial o. synovial chondromatosis



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteochondrosarcoma osteochondrosarcoma (os´te-o-kon´dro-sar-ko´-ma)
Chondrosarcoma arising in bone. Sarcomas in bone containing foci of neoplastic cartilage as well as bone are classified as osteogenic sarcomas. [osteo- + G. chondros, cartilage, + sarx, flesh, + -oma, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteochondrosis osteochondrosis (os´te-o-kon-dro´sis)
Any of a group of disorders of one or more ossification centers in children, characterized by degeneration or aseptic necrosis followed by reossification; includes the various forms of epiphysial aseptic necrosis. [osteo- + G. chondros, cartilage, + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteochondrous osteochondrous (os´te-o-kon´drus)
osseocartilaginous [osteo- + G. chondros, cartilage]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoclasis osteoclasis , osteoclasia (os´te-ok´la-sis, os´te-o-kla´ze-a)
Intentional fracture of a bone in order to correct deformity.diaclasis, diaclasia; [osteo- + G. klasis, fracture]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoclast osteoclast (os´te-o-klast)
1. A large multinucleated cell, possibly of monocytic origin, with abundant acidophilic cytoplasm, functioning in the absorption and removal of osseous tissue.osteophage; 2. An instrument used to fracture a bone to correct a deformity. [osteo- + G. klastos, broken]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoclastic osteoclastic (os´te-o-klas´tik)
Pertaining to osteoclasts, especially with reference to their activity in the absorption and removal of osseous tissue.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoclastoma osteoclastoma (os´te-o-klas-to´ma)
giant cell tumor of bone



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteocranium osteocranium (os´te-o-kra´ne-um)
The cranium of the fetus after ossification of the membranous cranium has made it firm. [osteo- + G. kranion, skull]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteocystoma osteocystoma (os´te-o-sis-to´ma)
solitary bone cyst



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteocyte osteocyte (os´te-o-sIt)
A cell of osseous tissue that occupies a lacuna and has cytoplasmic processes that extend into canaliculi and make contact by means of gap junctions with the processes of other osteocytes.bone cell, bone corpuscle, osseous cell; [osteo- + G. kytos, cell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteodentin osteodentin (os´te-o-den´tin)
Rapidly formed tertiary dentin that contains entrapped odontoblasts and few dentinal tubules, thereby superficially resembling bone. [osteo- + L. dens, tooth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteodermatopoikilosis osteodermatopoikilosis (os´te-o-der´ma-to-poy-ki-lo´sis) [MIM*166700]
Osteopoikilosis with skin lesions, most commonly small elastic fibrous nodules on the posterior aspects of the thighs and buttocks; irregular autosomal dominant inheritance.Buschke-Ollendorf syndrome; [osteo- + G. derma, skin, + poikilos, dappled, + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteodermatous osteodermatous (os´te-o-der´ma-tus)
Pertaining to or characterized by osteodermia.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteodermia osteodermia (os´te-o-der´me-a)
osteoma cutis [osteo- + G. derma, skin]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteodesmosis osteodesmosis (os´te-o-dez-mo´sis)
Transformation of tendon into bony tissue. [osteo- + G. desmos, a band (tendon), + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteodiastasis osteodiastasis (os´te-o-dI-as´ta-sis)
Separation of two adjacent bones, as of the cranium. [osteo- + G. diastasis, a separation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteodynia osteodynia (os-te-o-din´e-a)
ostealgia [osteo- + G. odyne, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteodysplasty osteodysplasty (os´te-o-dis´plas-te)
A generalized skeletal dysplasia with prominent forehead and small mandible; radiographically, there are irregular ribbon-like constrictions of the ribs and tubular bones; probably autosomal dominant inheritance. There are arguably two forms, autosomal recessive [MIM*249420] and X-linked [MIM*309350].Melnick-Needles syndrome; [osteo- + G. dys-, bad, + plastos, formed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteodystrophia osteodystrophia (os´te-o-dis-tro´fe-a)
osteodystrophy



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteodystrophy osteodystrophy (os´te-o-dis´tro-fe)
Defective formation of bone; common in dogs with chronic nephritis.osteodystrophia; [osteo- + G. dys, difficult, imperfect, + trophe, nourishment]
Albright's hereditary o. an inherited form of hyperparathyroidism associated with ectopic calcification and ossification and skeletal defects, notably the small fourth metacarpals, but intelligence is normal. There are dominant [MIM*103580 and *139320.001], recessive [MIM*203330] and X-linked [MIM*300800] forms. See also pseudohypoparathyroidism.Albright's syndrome (2);
renal o. generalized bone changes resembling osteomalacia and rickets or osteitis fibrosa, occurring in children or adults with chronic renal failure.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoectasia osteoectasia (os´te-o-ek-ta´ze-a)
Bowing of bones, particularly of the legs. [osteo- + G. ektasis, a stretching]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoectomy osteoectomy (os-te-o-ek´to-me)
ostectomy



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoepiphysis osteoepiphysis (os´te-o-e-pif´i-sis)
An epiphysis of a bone.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteofibroma osteofibroma (os´te-o-fI-bro´ma)
A benign lesion of bone, probably not a true neoplasm, consisting chiefly of fairly dense, moderately cellular, fibrous connective tissue in which there are small foci of osteogenesis. Most examples of this condition, especially in the maxilla and mandible, probably represent foci of fibrous dysplasia; a few examples of fibrous lesions with foci of osteogenesis, especially in vertebral bodies, may be neoplasms.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteofibrosis osteofibrosis (os´te-o-fI-bro´sis)
Fibrosis of bone, mainly involving red bone marrow.
periapical o. periapical cemental dysplasia



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteogen osteogen (os´te-o-jen)
A bone matrix-producing tissue or layer. [osteo- + G. -gen, producing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteogenesis osteogenesis (os´te-o-jen´e-sis)
The formation of bone.osteogeny, osteosis (2), ostosis (2); [osteo- + G. genesis, production]
o. imperfec´ta a large and miscellaneous group of conditions of abnormal fragility and plasticity of bone, with recurring fractures on trivial trauma; variable associated features include deformity of long bones, blueness of sclerae [MIM 166200], laxity of ligaments, and otosclerosis; inheritance is autosomal dominant in most families [MIM*120150, *120160, 166200, 166210-166230], but rare autosomal recessive types also exist [MIM 259400-259450]; there is an alteration in procollagen and collagen. In o. imperfecta congenita , a more severe form [MIM 166230], the fractures occur before or at birth; in o. imperfecta tarda , a less severe form, the fractures occur later in childhood. More recently classified as o. imperfecta types I, II, III, and IV based on the mode of inheritance as well as on clinical and biochemical criteria.brittle bones;



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteogenic osteogenic , osteogenetic (os´te-o-jen´ik, -je-net´ik)
Relating to osteogenesis.osteogenous, osteoplastic (1);



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteogenous osteogenous (os-te-oj´e-nus)
osteogenic



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteogeny osteogeny (os-te-oj´e-ne)
osteogenesis



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteography osteography (os´te-og´ra-fe)
A treatise on or description of the bones. [osteo- + G. graphe, a writing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteohalisteresis osteohalisteresis (os´te-o-hal´is-ter-e´sis)
Softening of the bones through absorption or insufficient supply of the mineral portion. [osteo- + G. hals, salt, + steresis, privation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteohypertrophy osteohypertrophy (os´te-o-hI-per´tro-fe)
Condition characterized by overgrowth of bones. [osteo- + G. hyper- over, + trophe, nourishment]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoid osteoid (os´te-oyd)
1. Relating to or resembling bone.ossiform; 2. Newly formed organic bone matrix prior to calcification. [osteo- + G. eidos, resemblance]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteolathyrism osteolathyrism (os´te-o-lath´i-rizm)
An experimental disease in rats, swine, turkeys, and other animals fed the seeds of certain species of Lathyrus (e.g., L. odoratus, sweet pea), or such nitriles as aminoacetonitrile or beta-aminopropionitrile; the chief pathologic changes occur in connective tissue structures, as follows: 1) fibroblastic, chondroblastic, and osteoblastic proliferative changes in the periosteum; 2) degeneration, necrosis, and atypical proliferation of epiphysial cartilages; 3) an increase in adipose tissue of the bone marrow; 4) sometimes proliferation of synovial membranes; 5) relatively large foci of extensive destruction of elastic fibers in the aorta, especially in the thoracic aorta. [osteo- + lathyrism]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteolipochondroma osteolipochondroma (os´te-o-lip´o-kon-dro´ma)
A benign neoplasm of cartilaginous tissue, in which metaplasia occurs and foci of adipose cells and osseous tissue are formed. [osteo- + G. lipos, fat, + chondros, cartilage, + -oma, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteologia osteologia (os-te-o-lo´je-a) [NA]
osteology, osteology [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteologist osteologist (os´te-ol´o-jist)
A specialist in osteology.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteology osteology (os´te-ol´o-je)
The anatomy of the bones; the science concerned with the bones and their structure.osteologia [NA]; [osteo- + G. logos, study]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteolysis osteolysis (os-te-ol´i-sis)
Softening, absorption, and destruction of bony tissue, a function of the osteoclasts. [osteo- + G. lysis, dissolution]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteolytic osteolytic (os-te-o-lit´ik)
Pertaining to, characterized by, or causing osteolysis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoma osteoma (os-te-o´ma)
A benign slow-growing mass of mature, predominantly lamellar bone, usually arising from the skull or mandible. [osteo- + G. -oma, tumor]
o. cu´tis cutaneous ossification usually secondary to calcification in foci of degeneration in tumors or inflammatory lesions or rarely primary new bone formation with normal skin.dermostosis, osteodermia, osteosis cutis;
dental o. an exostosis arising from the root of a tooth.
giant osteoid o. osteoblastoma
o. medulla´re an o. containing spaces that are filled (or partly filled) with various elements of bone marrow.
osteoid o. a painful benign neoplasm that usually originates in one of the bones of the lower extremities, especially the femur or tibia of adolescent and young adult persons; characterized by a nidus (usually no larger than 1 cm in diameter) that consists of osteoid material, vascularized osteogenic stroma, and poorly formed bone; around the nidus there is a relatively large zone of reactive thickening of the cortex.
o. spongio´sum an o. that consists chiefly of cancellous bone tissue.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteomalacia osteomalacia (os´te-o-ma-la´she-a)
A disease characterized by a gradual softening and bending of the bones with varying severity of pain; softening occurs because the bones contain osteoid tissue which has failed to calcify due to lack of vitamin D or renal tubular dysfunction; more common in women than in men, o. often begins during pregnancy.adult rickets, late rickets, rachitis tarda; [osteo- + G. malakia, softness]
infantile o. , juvenile o. rickets
senile o. osteoporosis in the aged.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteomalacic osteomalacic (os´te-o-ma-la´sik)
Relating to, or suffering from, osteomalacia.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteomatoid osteomatoid (os-te-o´ma-toyd)
An abnormal nodule or small mass of overgrowth of bone, usually occurring bilaterally and symmetrically, in juxtaepiphysial regions, especially in long bones of the lower extremities; lesions are not actually neoplasms, but represent anomalous developments in which there are outpouchings of the cortex (in contrast to a growth superimposed on the cortex), and are more properly termed exostoses. [osteoma + G. eidos, appearance, form]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteomere osteomere (os´te-o-mer)
One of the series of bone segments, such as the vertebrae. [osteo- + G. meros, a part]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteometry osteometry (os-te-om´e-tre)
The branch of anthropometry concerned with the relative size of the different parts of the skeleton. [osteo- + G. metron, measurement]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteomyelitis osteomyelitis (os´te-o-mI-e-lI´tis)
Inflammation of the bone marrow and adjacent bone.central osteitis (1); [osteo- + G. myelos, marrow, + -itis, inflammation]
chronic diffuse sclerosing o. a proliferative reaction of bone to a low-grade infection of the jaws; most often seen in middle-aged or older black women as extensive, often bilateral radio-opacities of the mandible and maxilla.
chronic focal sclerosing o. a reaction of bone to a mild bacterial infection, often the result of a carious tooth, in persons with a high degree of tissue resistance; results in a localized radio-opacity.focal condensing osteitis;
Garré's o. chronic o. with proliferative periostitis. A focal gross thickening of the periosteum with peripheral reactive bone formation resulting from mild infection.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteomyelodysplasia osteomyelodysplasia (os´te-o-mI´e-lo-dis-pla´-ze-a)
A disease characterized by enlargement of the marrow cavities of the bones, thinning of the osseous tissue, large, thin-walled vascular spaces, leukopenia, and irregular fever. [osteo- + G. myelos, marrow, + dysplasia]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteon osteon , osteone (os´te-on, -on)
A central canal containing blood capillaries and the concentric osseous lamellae around it occurring in compact bone.haversian system; [G. osteon, bone]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoncus osteoncus (os-te-ong´kus)
An osteoma, sometimes used with reference to any neoplasm of a bone. [osteo- + G. onkos, bulk (swelling)]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteonecrosis osteonecrosis (os´te-o-ne-kro´sis)
The death of bone in mass, as distinguished from caries ("molecular death") or relatively small foci of necrosis in bone. [osteo- + G. nekrosis, death]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteonectin osteonectin
A protein (MW 39,000-40,000) found in bone and nonmineralized tissues and believed to play a role in mineralization.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteopath osteopath (os´te-o-path)
osteopathic physician



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteopathia osteopathia (os´te-o-path´e-a)
osteopathy (1)
o. conden´sans osteopoikilosis
o. hemorrha´gica infan´tum infantile scurvy
o. stria´ta linear striations seen radiographically in the metaphyses of long bones and also flat bones; it may be a variant of osteopoikilosis.Voorhoeve's disease;



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteopathic osteopathic (os-te-o-path´ik)
Relating to osteopathy.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteopathology osteopathology (os´te-o-pa-thol´o-je)
Study of diseases of bone.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteopathy osteopathy (os-te-op´a-the)
1. Any disease of bone.osteopathia; 2. A school of medicine based upon a concept of the normal body as a vital machine capable, when in correct adjustment, of making its own remedies against infections and other toxic conditions; practitioners use the diagnostic and therapeutic measures of conventional medicine in addition to manipulative measures.osteopathic medicine; [osteo- + G. pathos, suffering]
alimentary o. bone disease due to dietary deficiency.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteopedion osteopedion (os´te-o-pe´de-on)
Archaic term for lithopedion. [osteo- + G. paidion, dim. of pais, a child]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteopenia osteopenia (os´te-o-pe´ne-a)
1. Decreased calcification or density of bone; a descriptive term applicable to all skeletal systems in which such a condition is noted; carries no implication about causality. 2. Reduced bone mass due to inadequate osteoid synthesis. [osteo- + G. penia, poverty]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoperiostitis osteoperiostitis (os´te-o-per´e-os-tI´tis)
Inflammation of the periosteum and of the underlying bone.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteopetrosis osteopetrosis (os´te-o-pe-tro´sis) [MIM*166600]
Excessive formation of dense trabecular bone and calcified cartilage, especially in long bones, leading to obliteration of marrow spaces and to anemia, with myeloid metaplasia and hepatosplenomegaly, beginning in infancy and with progressive deafness and blindness; autosomal recessive inheritance. There are autosomal recessive forms which may be mild [MIM*259310] or lethal [MIM*259720] and sometimes involves a renal tubular defect [MIM*259730]. A milder, autosomal domimant form has onset in childhood and no neurologic sequelae.Albers-Schönberg disease, marble bone disease, marble bones; [osteo- + G. petra, stone, + -osis, condition]
o. ac´ro-osteoly´tica pyknodysostosis
o. gallina´rum a virus-induced bone tumor of chickens. See also avian leukosis.
o. with renal tubular acidosis carbonic anhydrase II deficiency syndrome



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteopetrotic osteopetrotic (os´te-o-pe-trot´ik)
Relating to osteopetrosis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteophage osteophage (os´te-o-faj)
osteoclast (1) [osteo- + G. phago, to eat]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteophagia osteophagia (os´te-o-fa´je-a)
Eating of bones; perverted appetite seen in cattle suffering from mineral (phosphorus or calcium) deficiency. [osteo- + G. phago, to eat]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteophlebitis osteophlebitis (os´te-o-fle-bI´tis)
Inflammation of the veins of a bone. [osteo- + G. phleps, vein, + -itis, inflammation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteophony osteophony (os´te-of´o-ne)
bone conduction



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteophyma osteophyma (os-te-o-fI´ma)
osteophyte [osteo- + G. phyma, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteophyte osteophyte (os´te-o-fIt)
A bony outgrowth or protuberance.osteophyma; [osteo- + G. phyton, plant]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoplaque osteoplaque (os´te-o-plak)
Any osseous layer. [osteo- + Fr. plaque, plate]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoplast osteoplast (os´te-o-plast)
osteoblast [osteo- + G. plastos, formed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoplastic osteoplastic (os-te-o-plas´tik)
1. osteogenic 2. Relating to osteoplasty.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoplasty osteoplasty (os´te-o-plas-te)
1. Bone grafting; reparative or plastic surgery of the bones. 2. In dentistry, resection of osseous structure to achieve acceptable gingival contour. [osteo- + G. plastos, formed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteopoikilosis osteopoikilosis (os´te-o-poy-ki-lo´sis)
Mottled or spotted bones caused by widespread small foci of compact bone in the substantia spongiosa; autosomal dominant inheritance [MIM*166700]. See also osteopathia striata, dermatofibrosis lenticularis disseminata.osteopathia condensans; [osteo- + G. poikilos, dappled, + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoponin osteoponin
A protein produced by osteoblasts of unknown function.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteopontin osteopontin
A secreted phosphoprotein, produced by many epithelial cell types, that is highly negatively charged and frequently associated with mineralization processes. It is found in plasma, urine, milk, and bile. Transformed cells express o. in elevated levels.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoporosis osteoporosis (os´te-o-po-ro´sis)
Reduction in the quantity of bone or atrophy of skeletal tissue; occurs in postmenopausal women and elderly men, resulting in bone trabeculae that are scanty, thin, and without osteoclastic resorption. [osteo- + G. poros, pore, + -osis, condition]
o. circumscrip´ta cra´nii localized cranial o. often seen in Paget's disease.
juvenile o. idiopathic o. with onset before puberty, leading to pain or fractures, with spontaneous remission within a few years.
posttraumatic o. Sudeck's atrophy



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoporotic osteoporotic (os´te-o-po-rot´ik)
Pertaining to, characterized by, or causing a porous condition of the bones.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoradiologist osteoradiologist (os´te-o-ra-de-ol´o-jist)
A physician who specializes in radiology of the bones and joints. [osteo- + radiologist]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoradiology osteoradiology
The clinical subspecialty of diagnostic bone radiology.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteoradionecrosis osteoradionecrosis (os´te-o-ra´de-o-ne-kro´sis)
Necrosis of bone produced by ionizing radiation; may be planned or unplanned. [osteo- + radionecrosis]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteorrhaphy osteorrhaphy (os-te-or´a-fe)
Wiring together the fragments of a broken bone.osteosuture; [osteo- + G. rhaphe, suture]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteosarcoma osteosarcoma (os´te-o-sar-ko´ma)
osteogenic sarcoma
parosteal o. low grade o. arising on the surface of bone without involvement of the underlying marrow, usually occurring as a heavily ossified mass of the distal femur in women in the third and fourth decades of life.
periosteal o. chondroblastic o. occurring on the surface of bones without involvement of the marrow; usually presents in adolescents and young adults as a lucent defect with bone spicules extending into soft tissues. Histologically, the tumor is intermediate to high grade, and the cartilage is lobulated.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteosclerosis osteosclerosis (os´te-o-skle-ro´sis)
Abnormal hardening or eburnation of bone. [osteo- + G. sklerosis, hardness]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteosclerotic osteosclerotic (os´te-o-skle-rot´ik)
Relating to, due to, or marked by hardening of bone substance.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteosis osteosis (os-te-o´sis)
1. A morbid process in bone.ostosis (1); 2. osteogenesis [osteo- + G. -osis, condition]
o. cu´tis osteoma cutis
o. eburni´sans monomel´ica melorheostosis
parathyroid o. osteitis fibrosa cystica
renal fibrocystic o. renal rickets



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteospongioma osteospongioma (os´te-o-spon´je-o´ma)
General nonspecific term for a neoplasm in bone that results in thinning and fragmentation (thus, in softening) of the cortex. [osteo- + G. spongos, sponge, + -oma, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteosteatoma osteosteatoma (os´te-o-ste´a-to´ma)
A benign mass, usually a lipoma or sebaceous cyst, in which small foci of bony elements are present. [osteo- + G. stear, suet, fat, + -oma, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteosuture osteosuture (os-te-o-su´chur)
osteorrhaphy



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteosynthesis osteosynthesis (os-te-o-sin´the-sis)
Internal fixation of a fracture by means of a mechanical device, such as a pin, screw, or plate.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteothrombosis osteothrombosis (os´te-o-throm-bo´sis)
Thrombosis in one or more of the veins of a bone.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteotome osteotome (os´te-o-tom)
An instrument for use in cutting bone. [osteo- + G. tome, incision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteotomy osteotomy (os-te-ot´o-me)
Cutting a bone, usually by means of a saw or chisel. [osteo- + G. tome, incision]
"C" sliding o. an extraoral o. in the shape of a "C" performed bilaterally in the mandibular rami for the correction of retrognathia and/or apertognathia.
horizontal o. an o. performed intraorally for genioplasty; the inferior aspect of the anterior mandible is advanced or retruded by movement of the free segment.
Le Fort o. an o. often done to correct a maxillary skeletal deformity. Classified as Le Fort o. I, II, or III, depending upon the location.
sagittal split mandibular o. an intraoral surgical procedure for correction of retrognathism, apertognathia, and prognathism; the mandibular rami and posterior body are sectioned in the sagittal plane.
segmental alveolar o. an intraoral surgical procedure in which segments of alveolar bone containing teeth are sectioned between, and apically to, the teeth for the repositioning of the alveolus and teeth; it may be maxillary or mandibular, and may be combined with ostectomy.
sliding oblique o. an oral surgical procedure in which the mandibular ramus is cut vertically from the sigmoid notch to the angle to facilitate posterior repositioning of the mandible in correction of mandibular prognathism; it may be performed extraorally or intraorally, and is similar to vertical o.
vertical o. an oral surgical procedure similar to sliding oblique o.



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteotribe osteotribe (os´te-o-trIb)
An instrument for crushing off bits of necrosed or carious bone. [osteo- + G. tribo, to bruise, to grind down]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteotrite osteotrite (os´te-o-trIt)
An instrument with conical or olive-shaped tip having a cutting surface, resembling a dental burr, used for the removal of carious bone. [osteo- + L. tritus, a grinding, a wearing off]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteotrophy osteotrophy (os-te-ot´ro-fe)
Nutrition of osseous tissue. [osteo- + G. trophe, nourishment]



Copyright© 1995 Williams & Wilkins. All rights reserved.

osteotympanic osteotympanic (os´te-o-tim-pan´ik)
otocranial [osteo- + G. tympanon, drum]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ostertagia Ostertagia (os-ter-ta´je-a)
The medium or brown stomach worm; a genus of small, slender, bloodsucking trichostrongyle nematodes found in the abomasum (rarely in the small intestine) of sheep, goats, cattle, and other ruminants. Species include O. bisonis in bison, cattle, and deer; O. circumcincta, the most economically important species found in sheep, which occurs worldwide in sheep, goats, camels, and wild ruminants; O. lyrata in cattle and wild ruminants; O. occidentalis in sheep, goats, pronghorn, mule deer, and other ruminants; O. orloffi in sheep, cattle, mule deer, and Barbary sheep in North America and the area formerly known as the USSR; O. ostertagi, in cattle, sheep, and many wild ruminants; and O. trifurcata in sheep and goats, also reported from many wild ruminants. [R. von Ostertag]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostia ostia (os´te-a)
Plural of ostium. [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostial ostial (os´te-al)
Relating to any orifice, or ostium.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostitic ostitic (os-tI´tik)
osteitic



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostitis ostitis (os-tI´tis)
osteitis



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostium ostium, pl. ostia (os´te-um, -a) [NA]
A small opening, especially one of entrance into a hollow organ or canal. [L. door, entrance, mouth]
o. abdomina´le tu´bae uteri´nae [NA] abdominal o. of uterine tube
abdominal o. of uterine tube the fimbriated or ovarian extremity of an oviduct.o. abdominale tubae uterinae [NA];
o. aor´tae [NA] aortic orifice
aortic o. aortic orifice
o. appen´dicis vermifor´mis [NA] o. of vermiform appendix
o. arterio´sum mitral orifice
o. atrioventricula´re dex´trum [NA] tricuspid orifice
o. atrioventricula´re sinis´trum [NA] mitral orifice
o. cardi´acum [NA] cardiac orifice
o. ileoceca´le [NA] ileocecal orifice
o. inter´num uterine o. of uterine tubes
o. pharyn´geum tu´bae auditi´vae [NA] pharyngeal opening of auditory tube
o. pri´mum interatrial foramen primum
o. pylor´icum [NA] pyloric orifice
o. secun´dum interatrial foramen secundum
o. trun´ci pulmona´lis [NA] opening of pulmonary trunk
o. tympan´icum tu´bae auditi´vae [NA] tympanic opening of auditory tube
o. ure´teris [NA] ureteric orifice
o. ure´thrae exter´num [NA] external urethral orifice
o. ure´thrae inter´num [NA] internal urethral orifice
o. u´teri [NA] external os of uterus
o. u´teri exter´num external os of uterus
o. u´teri inter´num isthmus of uterus
uterine o. of uterine tubes the uterine opening of the oviduct.o. uterinum tubae [NA], o. internum, uterine opening of uterine tubes;
o. uteri´num tu´bae [NA] uterine o. of uterine tubes
o. vagi´nae [NA] vaginal orifice
o. ve´nae ca´vae inferio´ris [NA] opening of inferior vena cava
o. ve´nae ca´vae superio´ris [NA] opening of superior vena cava
os´tia vena´rum pulmona´lium [NA] openings of pulmonary veins, under opening
o. veno´sum cordis tricuspid orifice
o. of vermiform appendix the opening of the vermiform appendix into the lumen of the cecum.o. appendicis vermiformis [NA];



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostomate ostomate (os´to-mat)
Term for one who has an ostomy. [L. ostium, mouth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostomy ostomy (os´to-me)
1. An artificial stoma or opening into the urinary or gastrointestinal canal, or the trachea. 2. Any operation by which a permanent opening is created between two hollow organs or between a hollow viscus and the skin externally, as in tracheostomy. [L. ostium, mouth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

-ostomy -ostomy
See -stomy.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostosis ostosis (os-to´sis)
1. osteosis (1) 2. osteogenesis



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostraceous ostraceous (os-tra´shus)
Denoting the heaping up of scales seen in psoriasis, which resembles the stratification of oyster shells. [Ostraeacea, group including the oysters]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ostreotoxism ostreotoxism (os´tre-o-tok´sizm)
Poisoning from eating infected or contaminated oysters. [G. ostreon, oyster, + toxikon, poison]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ostwald Ostwald
Friedrich Wilhelm, German physical chemist and Nobel laureate, 1853-1932. See O.'s solubility coefficient.



Copyright© 1995 Williams & Wilkins. All rights reserved.

OT OT
Abbreviation for occupational therapist or therapy; Koch's old tuberculin.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ot- ot-
The ear. See also auri-. [G. ous]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ota Ota
Masao T., Japanese dermatopathologist, 1885-1945. See Ota's nevus.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otalgia otalgia (o-tal´je-a)
earache [ot- + G. algos, pain]
geniculate o. geniculate neuralgia
reflex o. pain referred to the ear from disease in another part, most commonly laryngeal, tonsillar, or nasopharyngeal.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otalgic otalgic (o-tal´jik)
1. Relating to otalgia, or earache. 2. A remedy for earache.



Copyright© 1995 Williams & Wilkins. All rights reserved.

OTC OTC
Abbreviation for over the counter, pertaining to a drug available without a prescription.



Copyright© 1995 Williams & Wilkins. All rights reserved.

other-directed other-directed (odh´er-di-rek´ted)
Pertaining to a person readily influenced by the attitudes of others.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otic otic (o´tik)
Relating to the ear. [G. otikos, fr. ous, ear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Otis Otis
Arthur Brooks, U.S. respiratory physiologist, *1913. See Rahn-O. sample.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otitic otitic (o-tit´ik)
Relating to otitis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otitis otitis (o-tI´tis)
Inflammation of the ear. [ot- + G. -itis, inflammation]
adhesive o. inflammation of the middle ear caused by prolonged eustachian tube dysfunction resulting in permanent retraction of the eardrum and obliteration of the middle ear space.
aviation o. aerotitis media
o. desquamati´va o. externa with a copious brawny desquamation.
o. exter´na inflammation of the external auditory canal.swimmer's ear;
o. inter´na labyrinthitis
o. me´dia inflammation of the middle ear, or tympanum.
parasitic o. otoacariasis
reflux o. me´dia o. media caused by passage of nasopharyngeal secretions through the eustachian tube.
secretory o. me´dia serous o
serous o. inflammation of middle ear mucosa, often accompanied by accumulation of fluid, secondary to eustachian tube obstruction.secretory o. media;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oto- oto-
The ear. See also auri-. [G. ous]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otoacariasis otoacariasis (o´to-ak-a-rI´a-sis)
An infestation of the auditory canal of cats, dogs, foxes, and other animals by auricular mites, chiefly Otodectes cynotis, which infest the ears and cause considerable discomfort and tenderness; in extreme cases, they cause symptoms such as loss of appetite, wasting, and fits. See also otodectic mange.parasitic otitis;



Copyright© 1995 Williams & Wilkins. All rights reserved.

otoacoustic otoacoustic (o´to-a-ku-stik)
Referring to the very faint sounds produced by the ear; thought to represent mechanical vibrations in the cochlea.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otobiosis otobiosis (o´to-bI-o´sis)
Presence of larvae and the characteristic spiny nymphs of Otobius megnini in the external auditory canal of cattle, horses, cats, dogs, deer, coyotes, and other domestic and wild animals; they may remain in the ear for several months before dropping out to pupate and mature. Several records of human infection are known.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Otobius Otobius (o-to´be-us)
A genus of argasid ticks similar to Ornithodoros but characterized by a granulated integument, a hypostome that is vestigial in the adult but well developed in the spiny nymphs, and the absence of eyes and hood. Two species are recognized: O. lagophilus (the face tick of rabbits), and O. megnini, the spinose ear tick that causes otobiosis in horses, cattle, sheep, dogs, and some wild animals; it occurs in southwestern parts of the U.S., where it is an important pest, and is also distributed worldwide.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otocephaly otocephaly (o-to-sef´a-le)
Malformation characterized by markedly defective development of the lower jaw (micrognathia or agnathia) and the union or close approach of the ears (synotia) on the front of the neck. [oto- + G. kephale, head]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otocerebritis otocerebritis (o-to-ser-e-brI´tis)
otoencephalitis



Copyright© 1995 Williams & Wilkins. All rights reserved.

otoconia otoconia, gen. otoconium (o-to-ko´ne-a, -um)
statoliths



Copyright© 1995 Williams & Wilkins. All rights reserved.

otocranial otocranial (o-to-kra´ne-al)
Relating to the otocranium.osteotympanic;



Copyright© 1995 Williams & Wilkins. All rights reserved.

otocranium otocranium (o´to-kra´ne-um)
The bony case of the internal and middle ear, consisting of the petrous portion of the temporal bone. [oto- + G. kranion, cranium]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otocyst otocyst (o´to-sist)
1. Embryonic auditory vesicle. 2. A balancing organ, analogous to the utricle of mammals, possessed by certain invertebrates and containing grains of calcareous material or of sand. [oto- + G. kystis, a bladder]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Otodectes Otodectes (o-to-dek´tez)
A genus of ear mites (family Psoroptidae) consisting of a single species, O. cynotis, the cause of otodectic mange in dogs, cats, and other carnivores; the entire lifespan of this mite is spent in the ears (rarely on the body) of the host, where it feeds on epidermal debris; it can be found in the encrusted material scraped from infected ears. [oto- + dektes, beggar, receiver]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otodectic otodectic (o-to-dek´tik)
Of, relating to, or caused by mites of the genus Otodectes.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otodynia otodynia (o-to-din´e-a)
earache [oto- + G. odyne, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otoencephalitis otoencephalitis (o´to-en-sef-a-lI´tis)
Inflammation of the brain by extension of the process from the middle ear and mastoid cells.otocerebritis; [oto- + G. enkephalos, brain, + -itis, inflammation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otoganglion otoganglion (o´to-gang´gle-on)
otic ganglion



Copyright© 1995 Williams & Wilkins. All rights reserved.

otogenic otogenic , otogenous (o´to-jen´ik, o-toj´e-nus)
Of otic origin; originating within the ear, especially from inflammation of the ear. [oto- + G. -gen, producing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otolaryngologist otolaryngologist (o´to-lar-ing-gol´o-jist)
A physician who specializes in otolaryngology.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otolaryngology otolaryngology (o´to-lar-ing-gol´o-je)
The combined specialties of diseases of the ear and larynx, often including upper respiratory tract and many diseases of the head and neck, tracheobronchial tree, and esophagus. [oto- + G. larynx, + logos, study]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otoliths otoliths , otolites (o´to-lith, o´to-lIt)
statoliths [oto- + G. lithos, stone]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otologic otologic (o´to-loj´ik)
Relating to otology.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otologist otologist (o-tol´o-jist)
A specialist in otology.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otology otology (o-tol´o-je)
The branch of medical science concerned with the study, diagnosis, and treatment of diseases of the ear and related structures. [oto- + G. logos, study]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otomucormycosis otomucormycosis (o-to-myu´kor-mI-ko´sis)
Mucormycosis of the ear.



Copyright© 1995 Williams & Wilkins. All rights reserved.

-otomy -otomy
See -tomy.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otomycosis otomycosis (o´to-mI-ko´sis)
An infection due to a fungus in the external auditory canal, usually unilateral, with scaling, itching, and pain as the primary symptoms.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otoneuralgia otoneuralgia (o´to-nu-ral´je-a)
Earache of neuralgic origin, not caused by inflammation. [oto- + G. neuron, nerve, + algos, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otopalatodigital otopalatodigital (o´to-pal´a-to-dij´i-tal)
Relating to the ears, palate, and fingers.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otopathy otopathy (o-top´a-the)
Any disease of the ear. [oto- + G. pathos, suffering]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otopharyngeal otopharyngeal (o´to-fa-rin´je-al)
Relating to the middle ear and the pharynx.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otoplasty otoplasty (o´to-plas-te)
Reparative or plastic surgery of the auricle of the ear. [oto- + G. plastos, formed]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otorhinolaryngology otorhinolaryngology (o´to-rI´no-lar-ing -gol´o-je)
The combined specialties of diseases of the ear, nose, and larynx; including diseases of related structures of the head and neck. See also otolaryngology. [oto- + G. rhis, nose, + larynx, larynx, + logos, study]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otorrhea otorrhea (o-to-re´a)
A discharge from the ear. [oto- + G. rhoia, flow]
cerebrospinal fluid o. discharge of cerebrospinal fluid through the external auditory meatus or through the eustachian tube into the nasopharynx.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otosalpinx otosalpinx (o-to-sal´pingks)
auditory tube [oto- + G. salpinx, trumpet]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otosclerosis otosclerosis (o´to-skle-ro´sis)
A new formation of spongy bone about the stapes and fenestra vestibuli (ovalis), resulting in progressively increasing deafness, without signs of disease in the eustachian tube or tympanic membrane. See also Bezold's triad. [oto- + G. sklerosis, hardening]



Copyright© 1995 Williams & Wilkins. All rights reserved.

otoscope otoscope (o´to-skop)
An instrument for examining the drum membrane or auscultating the ear. [oto- + G. skopeo, to view]
Siegle's o. an ear speculum with a bulb attachment by which the air pressure can be varied, thus imparting movement to the membrana tympani, if intact, while under inspection.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otoscopy otoscopy (o-tos´ko-pe)
Inspection of the ear, especially of the drum membrane. [oto- + G. skopeo, to view]
pneumatic o. inspection of the ear with a device capable of varying air pressure against the eardrum. Imparting movement to the tympanic membrane suggests normal middle ear compliance; the lack of movement indicates either increased impedance or eardrum perforation.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otosteal otosteal (o-tos´te-al)
Relating to the ossicles of the ear. [oto- + G. osteon, bone]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ototoxic ototoxic (o´to-tok´sik)
Having a toxic action upon the ear. [oto- + G. toxikon, poison]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ototoxicity ototoxicity (o-to-tok-sis´i-te)
The property of being ototoxic.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Otto Otto
Adolph W., German surgeon, 1786-1845. See O. pelvis; O.'s disease.



Copyright© 1995 Williams & Wilkins. All rights reserved.

otto of rose otto of rose
oil of rose



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ottoson Ottoson
David, 20th century Swedish physiologist. See O. potential.



Copyright© 1995 Williams & Wilkins. All rights reserved.

O.U. O.U.
Abbreviation for Latin oculus uterque, each eye or both eyes.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ouabagenin ouabagenin (wa´ba-jen-in)
The aglycon obtained from the hydrolysis of the cardiac glycoside, ouabain; exerts cardiotonic activity.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ouabain ouabain (wah´ban, wah´bah-in)
C29H44O128H2O; G-strophanthin; acocantherin;a glycoside and African arrow poison from ouabaio, obtained from the wood of Acocanthera ouabaio or from the seeds of Strophanthus gratus; its action is qualitatively identical to that of strophanthus and the digitalis glycosides; used for rapid digitalization; often used in pharmacological studies due to water solubility.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Ouchterlony Ouchterlony
Orjan, Swedish bacteriologist, *1914. See O. method, technique, test, technique.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oul- oul-
For words beginning thus, see ulo-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ounce (oz.) ounce (oz.) (owns)
A weight containing 480 gr., or 1 / 12 pound troy and apothecaries' weight, or 4371 / 2 gr., 1 / 16 pound avoirdupois. The apothecary oz. (used in the USP) contains 8 dr. and is equivalent to 31.10349 g; the avoirdupois oz. is equivalent to 28.35 g. [L. uncia, the twelfth part (of a pound or foot) hence also inch]



Copyright© 1995 Williams & Wilkins. All rights reserved.

-ous -ous
1. Chemical suffix attached to the name of an element in one of its lower valencies. Cf. -ic (1). 2. Having much of. [L. -osus, full of, abounding]



Copyright© 1995 Williams & Wilkins. All rights reserved.

outlet outlet (owt´let)
An exit or opening of a passageway.
pelvic o. inferior pelvic aperture



Copyright© 1995 Williams & Wilkins. All rights reserved.

outlier outlier (owt´le-er)
An observation that differs so widely from all others in a set as to justify the conclusion that a gross error has occurred or that it comes from a different population.



Copyright© 1995 Williams & Wilkins. All rights reserved.

outpatient outpatient (owt´pa´shent)
A patient treated in a hospital dispensary or clinic instead of in a room or ward.



Copyright© 1995 Williams & Wilkins. All rights reserved.

out of phase out of phase
Not in phase, moving in opposite directions at the same time; 180° out of phase; a possible characteristic of two simultaneous oscillations of similar frequency.



Copyright© 1995 Williams & Wilkins. All rights reserved.

output output (owt´put)
The quantity produced, ejected, or excreted of a specific entity in a specified period of time or per unit time, e.g., urinary sodium o.; the opposite of intake or input.
cardiac o. the amount of blood ejected by the heart in a unit of time (i.e., the minute volume), usually expressed in liters per minute.minute o;
minute o. cardiac o
pacemaker o. electrical energy delivered into a standard load (500 ohms resistance).
stroke o. stroke volume



Copyright© 1995 Williams & Wilkins. All rights reserved.

ova ova (o´va)
Plural of ovum. [L.]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oval oval (o´val)
1. Relating to an ovum. 2. Egg-shaped, resembling in outline the longitudinal section of an egg.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovalbumin ovalbumin (o-val-byu´min)
The chief protein occurring in the white of egg and resembling serum albumin; also found in phosphorylated form.albumen, egg albumin;



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovalocyte ovalocyte (o´val-o-sIt)
elliptocyte [L. ovalis, oval, + G. kytos, cell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovalocytosis ovalocytosis (o´va-lo-sI-to´sis)
elliptocytosis



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovarialgia ovarialgia (o-var-e-al´je-a)
Pain in an ovary.oophoralgia; [ovario- + G. algos, pain]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovarian ovarian (o-var´e-an)
Relating to the ovary.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariectomy ovariectomy (o-var-e-ek´to-me)
Excision of one or both ovaries.oophorectomy, ovariosteresis; [ovario- + G. ektome, excision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovario- ovario- , ovari-
Ovary. See also oo-, oophor-. [L. ovarium]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariocele ovariocele (o-var´e-o-sel)
Hernia of an ovary. [ovario- + G. kele, hernia]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariocentesis ovariocentesis (o-var´e-o-sen-te´sis)
Puncture of an ovary or an ovarian cyst. [ovario- + G. kentesis, puncture]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariocyesis ovariocyesis (o-var´e-o-sI-e´sis)
ovarian pregnancy [ovario- + G. kyesis, pregnancy]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariodysneuria ovariodysneuria (o-var´e-o-dis-nu´re-a)
Ovarian pain or neuralgia. [ovario- + G. dys-, bad, + neuron, nerve]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariogenic ovariogenic (o-var´e-o-jen´ik)
Originating in the ovary. [ovario- + G. -gen, producing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariohysterectomy ovariohysterectomy (o-var´e-o-his-ter-ek´to-me)
Removal of ovaries and uterus.oophorohysterectomy; [ovario- + G. hystera, uterus, + ektome, excision]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariolytic ovariolytic (o-var´e-o-lit´ik)
Destructive to the ovary. [ovario- + G. lysis, dissolution]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovarioncus ovarioncus (o-var-e-ong´kus)
oophoroma [ovario- + G. onkos, tumor]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariopathy ovariopathy (o-var-e-op´a-the)
Any disease of the ovary.oophoropathy; [ovario- + G. pathos, suffering]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariorrhexis ovariorrhexis (o-var´e-o-rek´sis)
Rupture of an ovary. [ovario- + G. rhexis, rupture]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariosalpingectomy ovariosalpingectomy (o-var´e-o-sal-pin-jek´to-me)
Operative removal of an ovary and the corresponding oviduct.oophorosalpingectomy; [ovario- + salpingectomy]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariosalpingitis ovariosalpingitis (o-var´e-o-sal-pin-jI´tis)
Inflammation of ovary and oviduct.oophorosalpingitis; [ovario- + salpingitis]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariosteresis ovariosteresis (o-var´e-o-ste-re´sis)
ovariectomy [ovario- + G. steresis, deprivation, loss]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariostomy ovariostomy (o-var-e-os´to-me)
Establishment of a temporary fistula for drainage of a cyst of the ovary.oophorostomy; [ovario- + G. stoma, mouth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovariotomy ovariotomy (o-var-e-ot´o-me)
An incision into an ovary, e.g., a biopsy or a wedge excision.oophorotomy; [ovario- + G. tome, incision]
normal o. historically, removal of an apparently healthy ovary.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovaritis ovaritis (o-va-rI´tis)
oophoritis



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovarium ovarium, pl. ovaria (o-var´e-um, -a) [NA]
ovary [Mod. L. fr. ovum, egg]
o. biparti´tum an ovary separated into two distinct parts.
o. disjunc´tum an ovary partially or completely divided into two sections.
o. gyra´tum an ovary showing curved or irregular grooves or furrows.
o. loba´tum an ovary demarcated by deep furrows into two or more lobes.
o. masculi´num testicular appendage



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovary ovary (o´va-re)
One of the paired female reproductive glands containing the ova or germ cells; the o.'s stroma is a vascular connective tissue containing numbers of ovarian follicles enclosing the ova; surrounding this stroma is a more condensed layer of stroma called the tunica albuginea.ovarium [NA], female gonad, genital gland (2); [Mod. L. ovarium, fr. ovum, egg]
mulberry o. the type of o. produced by the administration of anterior pituitary extracts to immature rats; such an o. contains many more follicles than normal, with the follicles in various stages of development and with prominent corpora lutea on their surfaces, thus the perceived resemblance to a mulberry.
polycystic o. enlarged cystic o.'s, pearl white in color, with thickened tunica albuginea, characteristic of the Stein-Leventhal syndrome; clinical features are abnormal menses, obesity, and evidence of masculinization, such as hirsutism.
third o. an accessory o.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overbite overbite (o´ver-bIt)
vertical overlap



Copyright© 1995 Williams & Wilkins. All rights reserved.

overclosure overclosure (o´ver-klo-zher)
A decrease in occlusal vertical dimension.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overcompensation overcompensation (o´ver-kom-pen-sa´shun)
1. An exaggeration of personal capacity by which one overcomes a real or imagined inferiority. 2. The process in which a psychologic deficiency inspires exaggerated correction. See compensation.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overcorrection overcorrection (o´ver-ko-rek´shun)
In behavior modification treatment programs, especially those involving mentally retarded individuals, overlearning the desired target behavior beyond the set criterion to assure that the behavior will continue to meet the established criterion when the post-learning decrements and forgetting occur.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overdenture overdenture (o-ver-den´chur)
overlay denture



Copyright© 1995 Williams & Wilkins. All rights reserved.

overdetermination overdetermination (o´ver-de-ter´min-a´shun)
In psychoanalysis, ascribing the cause of a single behavioral or emotional reaction, mental symptom, or dream to the operation of two or more forces, that is, it is overdetermined (e.g., ascribing the nature of an emotional outburst not only to the immediate precipitant but also to a lingering inferiority complex).



Copyright© 1995 Williams & Wilkins. All rights reserved.

overdominance overdominance (o-ver-dom´i-nans)
That state in which the heterozygote has greater phenotype value and perhaps is more fit than the homozygous state for either of the alleles that it comprises. Cf. balanced polymorphism.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overdominant overdominant (o-ver-dom´i-nant)
Denoting heterozygous states that exhibit overdominance.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overdrive overdrive (o-ver-drIv)
An electrophysiologic pacing technique to exceed the rate of an abnormal pacemaker and so capture the territory controlled by that pacemaker (usually atrial).



Copyright© 1995 Williams & Wilkins. All rights reserved.

overeruption overeruption (o´ver-e-rup´shun)
Occlusal projection of a tooth beyond the line of occlusion.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overextension overextension (o-ver-eks-ten´shun)
hyperextension



Copyright© 1995 Williams & Wilkins. All rights reserved.

overgrafting overgrafting (o´ver-graft´ing)
Placing a second or additional grafts over a previously healed graft from which the epithelium has been removed, as with dermabrasion, to strengthen a split-thickness graft.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overhang overhang (o´ver-hang)
An excess of dental filling material beyond the cavity margin or normal tooth contour.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overhead projector overhead projector
epidiascope



Copyright© 1995 Williams & Wilkins. All rights reserved.

overhydration overhydration (o´ver-hI-dra´shun)
hyperhydration



Copyright© 1995 Williams & Wilkins. All rights reserved.

overjet overjet , overjut (o´ver-jet, o´ver-jut)
horizontal overlap



Copyright© 1995 Williams & Wilkins. All rights reserved.

overlap overlap (o´ver-lap)
1. Suturing of one layer of tissue above or under another to gain strength. 2. An extension or projection of one tissue over another.
horizontal o. the projection of the upper anterior and/or posterior teeth beyond their antagonists in a horizontal direction.overjet, overjut;
vertical o. 1. the extension of the upper teeth over the lower teeth in a vertical direction when the opposing posterior teeth are in contact in centric occlusion; 2. the distance that teeth lap over their antagonists vertically, especially for the distance that the upper incisal edges drop below the lower ones, but may also describe the vertical relations of opposing cusps; 3. the relationship of the maxillary incisors to the mandibular incisors when the incisal edges pass each other in centric occlusion.overbite;



Copyright© 1995 Williams & Wilkins. All rights reserved.

overlay overlay (o´ver-la)
An addition to an already existing condition.
emotional o. the emotional or psychological concomitant of an organic disability.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overlearning overlearning (o´ver-lern´ing)
In the psychology of memory, continuation of practice beyond the point where one is able to perform according to the specified criterion; typically, retention is longer after o. as compared with retention after practice only to the point of performance meeting the specified criterion.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overresponse overresponse (o´ver-re-spons´)
An abnormally strong reaction to a stimulus.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overriding overriding (o´ver-rI´ding)
1. Slippage of the lower fragment of a broken long bone upward and alongside the proximal portion. 2. Obsolete term denoting a fetal head which is palpable above the symphysis because of cephalopelvic disproportion.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oversensing oversensing (o´ver-sen´sing)
Sensing of electrical or magnetic signals, which normally should not be sensed by a pacemaker, but result in inappropriate inhibition of the pacemaker's output.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overshoot overshoot (o´ver-shut)
1. Generally, any initial change, in response to a sudden step change in some factor, that is greater than the steady-state response to the new level of that factor; common in systems in which inertia or a time lag in negative feedback outweighs any damping that may be present. Changes in a negative direction are sometimes distinguished by the term undershoot, and the two may alternate in an oscillatory fashion, as in the transient oscillations of a pendulum when released from an initial displacement. 2. Momentary reversal of the membrane potential of a cell (inside becoming positive rather than negative relative to the outside) during an action potential; considered a form of overshoot (1) because, before discovery of overshoot (2) , excitation was thought merely to depolarize the membrane to zero transmembrane potential.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Overton Overton
Charles E., German biologist in Sweden, 1865-1933. See Meyer-O. rule, theory of narcosis.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overtone overtone (o´ver-ton)
Any of the tones, other than the lowest or fundamental tone, of which a sound is composed.
psychic o. the mental associations related to any stimulus.



Copyright© 1995 Williams & Wilkins. All rights reserved.

overventilation overventilation (o´ver-ven-ti-la´shun)
hyperventilation



Copyright© 1995 Williams & Wilkins. All rights reserved.

overwintering overwintering (o´ver-win´ter-ing)
Persistence of an infectious agent in its vector for extended periods, such as the cooler winter months, during which the vector has no opportunity to be reinfected or to infect another host.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovi- ovi-
Egg. See also oo-, ovo-. [L. ovum]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovicidal ovicidal (o-vi-sI´dal)
Causing death of the ovum. [ovi- + L. caedo, to kill]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oviducal oviducal (o-vi-du´kal)
oviductal



Copyright© 1995 Williams & Wilkins. All rights reserved.

oviduct oviduct (o´vi-dukt)
uterine tube [ovi- + L. ductus, a leading, fr. duco, pp. ductus, to lead]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oviductal oviductal (o-vi-duk´tal)
Relating to a uterine tube.oviducal;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oviferous oviferous (o-vif´er-us)
Carrying, containing, or producing ova.ovigerous; [ovi- + L. fero, to carry]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oviform oviform (o´vi-form)
ovoid (2)



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovigenesis ovigenesis (o-vi-jen´e-sis)
oogenesis



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovigenetic ovigenetic , ovigenic (o-vi-je-net´ik, -jen´ik)
oogenetic



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovigenous ovigenous (o-vij´e-nus)
oogenetic



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovigerous ovigerous (o-vij´er-us)
oviferous



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovigerus ovigerus
cumulus oöphorus



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovine ovine (o´vIn)
Relating to sheep; sheeplike. [L. ovinus, relating to a sheep]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovinia ovinia (o-vin´e-a)
sheep-pox [L. ovinus, relating to a sheep]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oviparity oviparity (o-vi-par´i-te)
The quality of being oviparous. [ovi- + L. pario, to bear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oviparous oviparous (o-vip´a-rus)
Egg-laying; denoting those birds, fish, amphibians, reptiles, monotreme mammals, and invertebrates whose young develop in eggs outside of the maternal body. [L. oviparus, fr. ovum, egg, + pario, to bear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oviposit oviposit (o´vi-poz´it)
To lay eggs; applied especially to insects. [ovi- + L. pono, pp. positus, to place]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oviposition oviposition (o´vi-po-zish´un)
Act of laying or depositing eggs by insects.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovipositor ovipositor (o-vi-poz´i-tor, -tor)
A specialized female organ especially well developed in insects for laying or depositing eggs.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovist ovist (o´vist)
A preformationist who believed that the female sex cell contained a miniature body susceptible to growth when stimulated by semen.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovo- ovo-
Egg. See also oo-, ovi-. [L. ovum]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovocyte ovocyte (o´vo-sIt)
oocyte [ovo- + G. kytos, a hollow (cell)]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovoflavin ovoflavin (o-vo-fla´vin)
Riboflavin found in eggs.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovogenesis ovogenesis (o-vo-jen´e-sis)
oogenesis



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovoglobulin ovoglobulin (o-vo-glob´yu-lin)
Globulin in the white of egg.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovogonium ovogonium (o-vo-go´ne-um)
Obsolete term for oogonium. [ovo- + G. gone, generation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovoid ovoid (o´voyd)
1. An oval or egg-shaped form. 2. Resembling an egg.oviform; [ovo- + G. eidos, resemblance]
fetal o. the form of the fetus in utero; its length is about one-half of the length of the extended fetus.
Manchester o. an egg-shaped radium applicator for placement in the lateral vaginal fornices. [University of Manchester, England]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovolarviparous ovolarviparous (o´vo-lar-vip´a-rus)
Denoting certain nematodes and other invertebrates in which the eggs are hatched within the female, and the larvae developed or protected within the uterus until the correct time for their emergence. [ovo- + L. larva, a mask, + pario, to bear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovomucin ovomucin (o-vo-myu´sin)
A glycoprotein in the white of egg.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovomucoid ovomucoid (o-vo-myu´koyd)
A mucoprotein obtained from the white of egg.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovoplasm ovoplasm (o´vo-plazm)
Protoplasm of an unfertilized egg.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovoprotogen ovoprotogen (o-vo-pro´to-jen)
lipoic acid



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovosiston ovosiston (o-vo-sis´ton)
An oral contraceptive that consists of a mixture of a progestin and an estrogen.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovotestis ovotestis (o´vo-tes´tis)
Gonad in which both testicular and ovarian components are present; a form of hermaphroditism.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovotransferrin ovotransferrin (o´vo-trans-far´in)
conalbumin



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovovitellin ovovitellin (o´vo-vI-tel´in)
vitellin [ovo- + L. vitellus, yolk]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovoviviparous ovoviviparous (o´vo-vI-vip´a-rus)
Denoting those fish, amphibians, and reptiles that produce eggs which hatch within the body of the parent. [ovo- + L. viviparus, bringing forth alive, fr. vivus, alive, + pario, to bear]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovular ovular (ov´yu-lar, o´vyu-)
Relating to an ovule.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovulation ovulation (ov´yu-la´shun, o´vyu-)
Release of an ovum from the ovarian follicle.
anestrous o. discharge of ova occurring in animals without estrus.
paracyclic o. o. occurring in the menstrual cycle at any time other than the normally anticipated time; believed to be usually a psychogenic phenomenon.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovulatory ovulatory (ov´yu-la-to-re, o´vyu-)
Relating to ovulation.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovule ovule (ov´yul, o´vyu-)
1. The ovum of a mammal, especially while still in the ovarian follicle. 2. A small beadlike structure bearing a fancied resemblance to an o.ovulum; [Mod. L. ovulum, dim. of L. ovum, egg]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovulocyclic ovulocyclic (ov´yu-lo-sI´klik, o´vyu-)
Denoting any recurrent phenomenon associated with and occurring at a certain time within the ovulatory cycle, as, for example, ovulocyclic porphyria.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovulum ovulum, pl. ovula (ov´yu-lum, o´vyu-; -la)
ovule



Copyright© 1995 Williams & Wilkins. All rights reserved.

ovum ovum, gen. ovi, pl. ova (o´vum, -vI, -va)
The female sex cell. When fertilized by a spermatozoon, an o. is capable of developing into a new individual of the same species; during maturation, the o., like the spermatozoon, undergoes a halving of its chromosomal complement so that, at its union with the male gamete, the species number of chromosomes (46 in humans) is maintained; yolk contained in the ova of different species varies greatly in amount and distribution, which influences the pattern of the cleavage divisions. [L. egg]
alecithal o. an o. in which the yolk is nearly absent, consisting of only a few particles.
blighted o. a fertilized o. whose development has ceased at an early stage.
centrolecithal o. one in which the yolk is mostly located near the center of the egg, as in arthropods.
fertilized o. an o. impregnated by a spermatozoon.
isolecithal o. an o. in which the yolk is evenly distributed throughout the cytoplasm.
Peters' o. an o. with a presumptive fertilization age of about 13 days; for many years, it was one of very few young human embryos recovered in good condition and its study furnished many facts regarding early embryonic changes.
telolecithal o. an o. in which there is a large amount of yolk massed at the vegetative pole, as in the eggs of birds and reptiles.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Owen Owen
Sir Richard, English anatomist, 1804-1892. See O.'s lines, under line; contour lines of O., under line; interglobular space of O.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Owren Owren
Paul A., Norwegian hematologist, *1905. See O.'s disease.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxa- oxa-
Combining form inserted in names of organic compounds to signify the presence or addition of oxygen atom(s) in a chain or ring (as in ethers), not appended to either (as in ketones and aldehydes). See also hydroxy-, oxo-, oxy-. [English. oxygen]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxacillin sodium oxacillin sodium (ok-sa-sil´in)
5-Methyl-3-phenyl-4-isoxazolylpenicillin sodium;a semisynthetic penicillin used in the oral therapy of penicillin-resistant staphylococcal infections.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxalaldehyde oxalaldehyde (ok-sa-lal´de-hId)
glyoxal



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxalate oxalate (ok´sa-lat)
A salt of oxalic acid.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxalemia oxalemia (ok-sa-le´me-a)
The presence of an abnormally large amount of oxalates in the blood. [oxalate + G. haima, blood]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxalic acid oxalic acid (ok-sal´ik)
An acid, HOOC-COOH, found in many plants and vegetables, particularly in buckwheat (family Polygoniaceae) and Oxalis (family Oxalidaceae); used as a hemostatic in veterinary medicine, but toxic when ingested by man; also used in the removal of ink and other stains, and as a general reducing agent; salts of o.a. are found in renal calculi; accumulates in cases of primary hyperoxaluria.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxalo oxalo (ok´sa-lo)
The monoacyl radical, HOOC-C(O)-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxaloacetate transacetase oxaloacetate transacetase (ok´sa-lo-as´e-tat trans-as´e-tas)
citrate synthase



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxaloacetic acid oxaloacetic acid (ok´sa-lo-a-se´tik)
HOOC-CO-CH2COOH;a ketodicarboxylic acid and important intermediate in the tricarboxylic acid cycle; the product formed when l-aspartic acid acts as an amine donor in transamination reactions.ketosuccinic acid, oxosuccinic acid;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxalosis oxalosis (ok-sa-lo´sis)
Widespread deposition of calcium oxalate crystals in the kidneys, bones, arterial media, and myocardium, with increased urinary excretion of oxalate; may be an acquired disorder, as in oxalate poisoning, or represent one aspect of primary hyperoxaluria and o. [oxalate + -osis, condition]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxalosuccinic acid oxalosuccinic acid (ok´sa-lo-suk-sin´ik)
HOOC-CO-CH(COOH)-CH2-CO OH;the product of the dehydrogenation of isocitric acid under the catalytic influence of isocitrate dehydrogenase; an enzyme-bound intermediate of the tricarboxylic acid cycle.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxalosuccinic carboxylase oxalosuccinic carboxylase
isocitrate dehydrogenase



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxalourea oxalourea (ok´sa-lo-yu-re´a)
oxalylurea



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxaluria oxaluria (ok-sa-lu´re-a)
hyperoxaluria [oxalate + G. ouron, urine]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxaluric acid oxaluric acid (ok-sa-lur´ik)
NH2CONHCOCOOH;the ureide of oxalic acid, derived from uric acid or oxalylurea.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxalyl oxalyl (ok´sa-lil)
The diacyl radical, -CO-CO-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxalylurea oxalylurea (ok´sa-lil-yu-re´a)
The cyclic (end-to-end) amide anhydride of oxaluric acid; an oxidation product of uric acid.oxalourea, parabanic acid;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxamniquine oxamniquine (oks-am´ni-quin)
C14H21N3O3;a tetrahydroquinoline derivative, similar to hycanthone and lucanthone, effective against Schistosoma mansoni; now largely superseded by the broad spectrum anthelmintic drug praziquantel.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxanamide oxanamide (ok-san´a-mId)
2-Ethyl-3-propylglycidamide;a sedative.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxandrolone oxandrolone (ok-san´dro-lon)
17beta-Hydroxy-17a-methyl-2-oxa-5a-androstan-3-one (C-2 replaced by O in the androstane nucleus); an androgenic anabolic steroid.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxaphenamide oxaphenamide (ok-sa-fen´a-mId)
4´-Hydroxysalicylanilide;a choleretic.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxazepam oxazepam (ok-sa´ze-pam)
7-Chloro-1,3-dihydro-3-hydroxy-5-phenyl-2H-1,4-benzodiazepin-2-one;a benzodiazepine chemically and pharmacologically related to chlordiazepoxide and diazepam; an antianxiety agent.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxazin oxazin (ok´sa-zin)
C12H10ON2; Oxyiminodiphenylimine;parent substance of a series of biological dyes, e.g., gallocyanin, brilliant cresyl blue, cresyl violet acetate.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxazole oxazole (ok´sa-zol)
The fundamental ring system.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxazolidinediones oxazolidinediones (ok-sa-zo-lid´In-de-onz)
An obsolescent chemical class of antiepileptic drugs useful in the treatment of absence (petit mal) seizures; examples include trimethadione and paramethadione.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxeladin oxeladin (ok-sel´a-din)
2-Ethyl-2-phenylbutyric acid 2-(2-diethylaminoethoxy)ethyl ester;an antitussive agent.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxiconazole oxiconazole (ok´se-ko´na-zol)
Broad spectrum antifungal agent resembling ketoconazole.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxidant oxidant (ok´si-dant)
The substance that is reduced and that, therefore, oxidizes the other component of an oxidation-reduction system.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxidase oxidase (ok´si-das)
Classically, one of a group of enzymes, now termed oxidoreductases (EC class 1), that bring about oxidation by the addition of oxygen to a metabolite or by the removal of hydrogen or of one or more electrons. O. is now used for those cases in which O2 acts as an acceptor (of H or of electrons); those removing hydrogen are now termed dehydrogenases. For individual o.'s, see the specific names.
direct o. originally, an o. catalyzing the transfer of O2 directly to other bodies; now termed oxygenase.
indirect o. originally, an o. that acts by reducing a peroxide; now termed peroxidase.
terminal o. the last protein in the electron transport, respiratory chain. In mammals this is cytochrome c oxidase.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxidasis oxidasis (ok-si-da´sis)
Oxidation by an oxidase.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxidation oxidation (ok-si-da´shun)
1. Combination with oxygen; increasing the valence of an atom or ion by the loss from it of hydrogen or of one or more electrons thus rendering it more electropositive, as when iron is changed from the ferrous (2+) to the ferric (3+) state. 2. In bacteriology, the aerobic dissimilation of substrates with the production of energy and water; in contrast to fermentation, the transfer of electrons in the o. process is accomplished via the respiratory chain, which utilizes oxygen as the final electron acceptor.
alpha-o. , a-oxidation a form of o. of fatty acids in which carbons are removed one at a time in the form of CO2; the a-carbon is first hydroxylated and then converted into a carbonyl; a deficiency of this pathway is associated with Refsum's disease.
beta-o. , beta-oxidation 1. o. of the beta-carbon (carbon 3) of a fatty acid, forming the beta-keto (beta-oxo) acid analog; of importance in fatty acid catabolism; 2. the entire pathway for the catabolism of saturated fatty acids containing an even number of carbon atoms; beta-o. (1) is a part of this pathway; acetyl-CoA is a major product of this pathway.
end o. the last o. step in a catabolic pathway.terminal o;
omega-o. , omega-oxidation o. at the carbon atom farthest removed (omega-carbon) from the carboxyl group (carbon 1); thus, in this pathway, a dicarboxylic acid is formed; an important pathway in the degradation of prostaglandins.
terminal o. end o



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxidation-reduction oxidation-reduction
Any chemical oxidation or reduction reaction, which must, in toto, comprise both oxidation and reduction; the basis for calling all oxidative enzymes (formerly oxidases) oxidoreductases. Often shortened to "redox."



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxidative oxidative (ok-si-da´tiv)
Having the power to oxidize; denoting a process involving oxidation.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxide oxide (ok´sId)
A compound of oxygen with another element or a radical; e.g., mercuric o., HgO.
acid o. an acid anhydride; an o. of an electronegative element or radical; it can combine with water to form an acid.
basic o. a base anhydride; an o. of an electropositive element or radical; it can combine with water to form a base.
indifferent o. neutral o
neutral o. an o. that is neither an acid nor a base; e.g., water (hydrogen oxide, H2O).indifferent o;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxidize oxidize (ok´si-dIz)
To combine or cause an element or radical to combine with oxygen or to lose electrons.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxidoreductase oxidoreductase (ok´si-do-re-duk´tas)
An enzyme (EC class 1) catalyzing an oxidation-reduction reaction. Trivial names for o.'s include dehydrogenase, reductase, oxidase (where O2 is the H acceptor), oxygenase (where O2 is incorporated into the substrate), peroxidase (H2O2 is the acceptor; catalase is an exception), hydroxylase (coupled oxidation of two donors). See also oxidase.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxime oxime (ok´sem)
A compound resulting from the action of hydroxylamine, NH2OH, on a ketone or an aldehyde to yield the group =N-OH attached to the former carbonyl carbon atom.
amide o.'s amidoximes



Copyright© 1995 Williams & Wilkins. All rights reserved.

oximeter oximeter (ok-sim´e-ter)
An instrument for determining photoelectrically the oxygen saturation of a sample of blood.
cuvette o. an o. that reads the percentage of oxygen saturation of the blood as it passes through a cuvette outside the body.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oximetry oximetry (ok-sim´e-tre)
Measurement with an oximeter of the oxygen saturation of hemoglobin in a sample of blood.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxirane oxirane (oks´e-ran)
ethylene oxide



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxo- oxo-
Prefix denoting addition of oxygen; used in place of keto- in systematic nomenclature. See also hydroxy-, oxa-, oxy-.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxoacetic acid oxoacetic acid (ok´so-a-se´tik)
glyoxylic acid



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxo acid oxo acid (ok´so)
keto acid



Copyright© 1995 Williams & Wilkins. All rights reserved.

3-oxoacid-CoA transferase 3-oxoacid-CoA transferase
An enzyme catalyzing the reversible conversion of acetoacetyl-CoA and succinate into succinyl-CoA and acetoacetate; malonyl-CoA can substitute for succinyl-CoA and a few other 3-oxo acids for the acetoacetate; an important step in order for the ketone bodies to serve as a fuel for extrahepatic tissues.3-ketoacid-CoA transferase, acetoacetyl-succinic thiophorase;



Copyright© 1995 Williams & Wilkins. All rights reserved.

3-oxoacyl-ACP reductase 3-oxoacyl-ACP reductase (ok´so-as´il)
A part of the fatty acid synthase complex; an enzyme reversibly reacting 3-oxoacyl-ACP with NADPH to form d-3-hydroxyacyl-ACP and NADP+.beta-ketoacyl-ACP reductase;



Copyright© 1995 Williams & Wilkins. All rights reserved.

3-oxoacyl-ACP synthase 3-oxoacyl-ACP synthase
An enzyme condensing malonyl-ACP and acyl-cys-protein to 3-oxoacyl-ACP + cys-protein + CO2, and similar reactions, as steps in fatty acid synthesis; cys-protein is also a part of the fatty acid synthase complex.acyl-malonyl-ACP synthase, beta-ketoacyl-ACP synthase;



Copyright© 1995 Williams & Wilkins. All rights reserved.

2-oxoglutarate dehydrogenase 2-oxoglutarate dehydrogenase (ok´so-glu-tar´at)
a-ketoglutarate dehydrogenase



Copyright© 1995 Williams & Wilkins. All rights reserved.

2-oxoglutaric acid 2-oxoglutaric acid (oks´-o-glu-tar-ik)
a-ketoglutaramic acid



Copyright© 1995 Williams & Wilkins. All rights reserved.

2-oxo-5-guanidovaleric acid 2-oxo-5-guanidovaleric acid (gwan-e´do-va-ler´ik)
The deaminated derivative of arginine.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxolamine oxolamine (ok-sol´a-men)
5-(2-Diethylaminoethyl)-3-phenyl-1,2,4-oxadiazole;used for treatment of bronchopulmonary infections.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxolinic acid oxolinic acid (ok-so-lin´ik)
5-Ethyl-5,8-dihydro-8-oxo-1,3-dioxolo[4,5-g]quinoline-7-carboxylic acid;a quinolone antibacterial agent used in the treatment of urinary tract infections.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxophenarsine hydrochloride oxophenarsine hydrochloride (ok´so-fen-ar´sen)
3-Amino-4-hydroxyphenylarsineoxide hydrochloride;an antisyphilitic and antitrypanosomal agent.



Copyright© 1995 Williams & Wilkins. All rights reserved.

5-oxoprolinase 5-oxoprolinase
An enzyme that catalyzes the ATP-dependent hydrolysis of l-5-oxoproline (ATP + l-5-oxoproline -> ADP + Pi + l-glutamate) a deficiency of this enzyme will result in 5-oxoprolinuria.



Copyright© 1995 Williams & Wilkins. All rights reserved.

5-oxoproline (Glp) 5-oxoproline (Glp) (oks´o-pro´len)
A keto derivative of proline that is formed nonenzymatically from glutamate, glutamine, and gamma-glutamylated peptides; it is also produced by the action of gamma-glutamylcyclotransferase; elevated levels of 5-o. are often associated with problems of glutamine or glutathione metabolism.5-pyrrolidone-2-carboxylic acid, pyroglutamic acid, pyrrolidone-5-carboxylate;



Copyright© 1995 Williams & Wilkins. All rights reserved.

4-oxoproline reductase 4-oxoproline reductase
4-hydroxyproline oxidase



Copyright© 1995 Williams & Wilkins. All rights reserved.

5-oxoprolinuria 5-oxoprolinuria (oks´o-pro´len-yur-e-a)
Elevated levels of 5-oxoproline in the urine.



Copyright© 1995 Williams & Wilkins. All rights reserved.

17-oxosteroids 17-oxosteroids (ok-so-ster´oydz)
17-ketosteroids



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxosuccinic acid oxosuccinic acid (ok´so-suk-sin´ik)
oxaloacetic acid



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxotremorine oxotremorine (ok´so-trem´er-en)
An active metabolite of tremorine. Used as a pharmacological tool for producing a parkinson-like tremor.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxprenolol hydrochloride oxprenolol hydrochloride (oks-pren´o-lol)
1-[o-(Allyloxy)phenoxy]-3-(isopropylamino)-2-propanol hydrochloride;a beta-receptor blocking agent with coronary vasodilator activity.



Copyright© 1995 Williams & Wilkins. All rights reserved.

OXT OXT
Abbreviation for oxytocin.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxtriphylline oxtriphylline (oks-trI´fi-lin, oks´trI-fil´in)
A true salt of theophylline; it has mild diuretic, myocardial stimulating vasodilator, and bronchodilator actions, with the same uses as theophylline, but is better absorbed and less irritating.choline theophyllinate;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxy- oxy-
1. Combining form denoting shrill; sharp, pointed; quick (incorrectly used for ocy-, from G. okys, swift). 2. In chemistry, combining form denoting the presence of oxygen, either added or substituted, in a substance. See also hydroxy-, oxa-, oxo-. [G. oxys, keen]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyacoia oxyacoia , oxyakoia (ok´se-a-koy´a)
Increased sensitiveness to noises, occurring in facial paralysis, especially when the stapedius muscle is paralyzed. [G. oxys, acute, + akoe, hearing]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyaphia oxyaphia (ok-se-a´fe-a)
hyperaphia [G. oxys, acute, + haphe, touch]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxybarbiturates oxybarbiturates (ok´se-bar-bit´yur-ats)
Hypnotics of the barbiturate group in which the atom attached at the carbon-2 position is oxygen; virtually all hypnotic barbituates are o.'s.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxybenzone oxybenzone (ok-se-ben´zon)
2-Hydroxy-4-methoxybenzophenone;an ultraviolet screen for use in skin ointments and lotions.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxybiotin oxybiotin (ok-se-bI´o-tin)
An analogue and antimetabolite of biotin, in which the sulfur atom is replaced by oxygen.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxybutynin chloride oxybutynin chloride (ok-se-byu´ti-nin)
a-Phenylcyclohexaneglycolic acid 4-(diethylamino)-2-butynyl ester hydrochloride;an intestinal antispasmodic.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxycalorimeter oxycalorimeter (ok´se-kal-o-rim´e-ter)
A calorimeter measuring energy content of substances in terms of oxygen consumed.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxycellulose oxycellulose (ok-se-sel´yu-los)
Cellulose that has been oxidized by NO2 or other oxidizing agents to the point where all or most of the glucose residues have been converted to glucuronic acid residues; used as an adsorbent in chromatography or other adsorption processes. See also oxidized cellulose.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxycephalia oxycephalia (ok´se-se-fa´le-a)
oxycephaly



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxycephalic oxycephalic , oxycephalous (ok-se-se-fal´ik, -sef´a-lus)
Relating to or characterized by oxycephaly.acrocephalic, acrocephalous;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxycephaly oxycephaly (ok-se-sef´a-le)
A type of craniosynostosis in which there is premature closure of the lambdoid and coronal sutures, resulting in an abnormally high, peaked, or conically shaped skull.acrocephalia, acrocephaly, hypsicephaly, hypsocephaly, oxycephalia, steeple skull, tower skull, turricephaly; [G. oxys, pointed, + kephale, head]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxychloride oxychloride (ok-se-klor´Id)
A compound of oxygen with a metallic chloride; e.g., a chlorate or perchlorate.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxychromatic oxychromatic (ok´se-kro-mat´ik)
acidophilic [G. oxys, sour, acid, + chroma, color]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxychromatin oxychromatin (ok-se-kro´ma-tin)
Chromatin that stains with acid dyes, as in interphase nuclei.oxyphil chromatin;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxycodone oxycodone (ok-se-ko´don)
14-Hydroxydihydrocodeinone;a narcotic analgesic.



Copyright© 1995 Williams & Wilkins. All rights reserved.

11-oxycorticoids 11-oxycorticoids (ok-se-kor´ti-koydz)
Corticosteroids bearing an alcohol or ketonic group on carbon-11; e.g., cortisone, cortisol.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyesthesia oxyesthesia (ok´se-es-the´ze-a)
hyperesthesia [G. oxys, acute, + aisthesis, sensation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxygen (O) oxygen (O) (ok´se-jen)
1. A gaseous element, atomic no. 8, atomic wt. 15.9994 on basis of 12C = 12.0000; an abundant and widely distributed chemical element, which combines with most of the other elements to form oxides and is essential to animal and plant life. 2. The molecular form of o., O2. 3. A medicinal gas that contains not less than 99.0%, by volume, of O2. [G. oxys, sharp, acid and genes, forming]
heavy o. oxygen-18
hyperbaric o. , high pressure o. o. at a pressure greater than 1 atmosphere. See also hyperbaric oxygenation.
singlet o. an excited or higher energy form of o. characterized by the spin of a pair of electrons in opposite directions, whereas electron spin is unidirectional in normal molecular o. Because of its great reactivity, singlet o. is a probable intermediate in most photo-oxidation reactions. Although it exists for no more than 0.1 sec, it may react with atmospheric pollutants to foster smog formation and may have harmful biological effects.
triplet o. the normal unexcited state of O2 in the atmosphere, in which the unpaired pair of electrons are so displaced that their magnetic fields are oriented in the same direction, resulting in paramagnetism; each of the heat-generated spectral lines of such o. can be split by a magnetic field into a triplet. Cf. singlet o.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxygen-15 (15O) oxygen-15 (15O)
A cyclotron-produced, positron-emitting radioisotope of oxygen with a half-life of 122.2 seconds; used in studies of respiratory function and in positron emission tomography.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxygen-16 (16O) oxygen-16 (16O)
The common oxygen isotope, making up 99.76% of natural oxygen.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxygen-17 (17O) oxygen-17 (17O)
The rarest of the stable oxygen isotopes, making up 0.04% of natural oxygen.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxygen-18 (18O) oxygen-18 (18O)
A stable oxygen isotope making up 0.20% of natural oxygen; used in mass spectrometry and in NMR studies of tissue.heavy oxygen;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxygenase oxygenase (ok´se-je-nas)
One of a group of enzymes (EC subclass 1.13) catalyzing direct incorporation of O2 into substrates; e.g., tryptophan 2,3-dioxygenase (tryptophan pyrrolase) catalyzing reaction between O2 and l-tryptophan to form N-l-formylkynurenine. Cf. dioxygenase, monooxygenases.
mixed function o. any monooxygenase that catalyzes AH + O2 + DH2 -> AOH + H2O + D.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxygenate oxygenate (ok´se-je-nat)
To accomplish oxygenation.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxygenation oxygenation (ok´se-je-na´shun)
Addition of oxygen to any chemical or physical system.
apneic o. diffusion respiration
hyperbaric o. an increased amount of oxygen in organs and tissues resulting from the administration of oxygen in a compression chamber at an ambient pressure greater than 1 atmosphere.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxygenic oxygenic (ok-se-jen´ik)
Pertaining to or containing oxygen.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxygenize oxygenize (ok´se-jen-Iz)
To oxidize with oxygen.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxygeusia oxygeusia (ok-se-gu´se-a)
hypergeusia [G. oxys, acute, + geusis, taste]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyheme oxyheme (ok´se-hem)
hematin



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyhemochromogen oxyhemochromogen (ok´se-hem´o-kro´mo-jen)
hematin



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyhemoglobin (HbO2) oxyhemoglobin (HbO2) (ok´se-he-mo-glo´bin)
Hemoglobin in combination with oxygen, the form of hemoglobin present in arterial blood, scarlet or bright red when dissolved in water.oxygenated hemoglobin;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyiodide oxyiodide (ok-se-I´o-dId)
A compound of oxygen with a metallic iodide, e.g., an iodate or periodate.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxykrinin oxykrinin (ok-se-krin´in)
secretin



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyluciferin oxyluciferin (oks´e-lu-si´fer-in)
The activated derivative of luciferin formed in bioluminescence.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxymesterone oxymesterone (ok-se-mes´te-ron)
4,17beta-Dihydroxy-17-methylandrost-4-en-3-one;an anabolic steroid.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxymetazoline hydrochloride oxymetazoline hydrochloride (ok´se-me-taz´o-len)
6-Tert-butyl-3-(2-imidazolin-2-ylmethyl)-2,4-dimentylphenol hydrochloride;a vasoconstrictor used topically to reduce swelling and congestion of the nasal mucosa.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxymetholone oxymetholone (ok-se-meth´o-lon)
17beta-Hydroxy-2-(hydroxymethylene)-17-methyl-5a-androstan-3-one;an androgenic anabolic steroid.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxymorphone hydrochloride oxymorphone hydrochloride (ok-se-mor´fon)
14-Hydroxydihydromorphinone hydrochloride;a semisynthetic narcotic analgesic closely related chemically to hydromorphone hydrochloride; its actions are similar to those of morphine, but more potent.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxymyoglobin (MbO2) oxymyoglobin (MbO2) (ok´se-mI-o-glo´bin)
Myoglobin in its oxygenated form, analogous in structure to oxyhemoglobin.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxynervone oxynervone (ok´se-ner´von)
hydroxynervone



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyneurine oxyneurine (ok-se-nur´en)
betaine



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyntic oxyntic (ok-sin´tik)
Acid-forming, e.g., the parietal cells of the gastric glands. [G. oxyno, to sharpen, make sour, acid]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyosmia oxyosmia (ok-se-oz´me-a)
hyperosmia [G. oxys, acute + osme, sense of smell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyosphresia oxyosphresia (ok´se-os-fre´ze-a)
hyperosmia [G. oxys, acute, + osphresis, smell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxypertine oxypertine (ok-se-per´ten)
5,6-Dimethoxy-2-methyl-3-[2-(4-phenyl-1-piperazinyl)ethyl]indole;an antianxiety agent; also available as the hydrochloride.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyphenbutazone oxyphenbutazone (ok´se-fen-bu´ta-zon)
1-(p-Hydroxyphenyl)-2-phenyl-4-butyl-3,5-pyrazolidine-dione monohydrate;an orally effective analgesic and anti-inflammatory agent used (usually in short courses) for rheumatoid arthritis and gout.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyphencyclimine hydrochloride oxyphencyclimine hydrochloride (ok´se-fen-sI´klI-men)
The hydrochloride of 1,4,5,6-tetrahydro-1-methylpyrimidin-2-ylmethyl-a-cyclohexyl-a-hydroxy-a-phenylacetate; an anticholinergic agent.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyphenisatin acetate oxyphenisatin acetate (ok´se-fe-nI´sa-tin)
endophenolphthalein; diacetyldiphenolisatin; 3,3-bis(p-acetoxyphenyl)oxindole;a cathartic with pharmacologic properties resembling those of phenolphthalein, except that it is not absorbed from the gastrointestinal tract.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyphenonium bromide oxyphenonium bromide (ok´se-fe-no´ne-um)
Diethyl(2-hydroxyethyl)methylammonium bromide a-phenyl-a-cyclohexylglycolate;a quaternary ammonium compound with anticholinergic action.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyphil oxyphil , oxyphile (ok´se-fil, -fIl)
1. Oxyphil cell. 2. eosinophilic leukocyte 3. oxyphilic [G. oxys, sour, acid, + philos, fond]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyphilic oxyphilic (ok-se-fil´ik)
Having an affinity for acid dyes; denoting certain cell or tissue elements.oxyphil (3), oxyphile;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyphonia oxyphonia (ok-se-fo´ne-a)
Shrillness or high pitch of the voice. [G. oxys, sharp, + phone, voice]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxypolygelatin oxypolygelatin (ok´se-pol-e-jel´a-tin)
A modified gelatin used as a plasma extender in transfusions.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxypurine oxypurine (ok-se-pyur´en)
A purine containing oxygen; e.g., hypoxanthine, xanthine, uric acid.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxypurinol oxypurinol (ok´se-pur´I-nol)
Alloxanthine and inhibitor of xanthine oxidase; an active metabolite of allopurinol. The drug inhibits the formation of uric acid and is used in the treatment of gout.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyrhine oxyrhine (ok´se-rIn)
Having a sharp-pointed nose. [G. oxys, sharp, + rhis (rhin-), nose]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyrygmia oxyrygmia (ok-se-rig´me-a)
Obsolete term for eructation of acid fluid. [G. oxys, acid, + erygmos, eructation]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oxyspirura mansoni Oxyspirura mansoni (ok´-se-spI-ru´ra man-so´nI)
A widely distributed spiruroid nematode parasite found under the nictitating membrane in the eye of turkeys, chickens, peafowl, quail, and grouse; larvae develop to the infective stage in cockroaches.Manson's eye worm;



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxytalan oxytalan (ok-sit´a-lan)
A type of connective tissue fiber histochemically distinct from collagen or elastic fibers described in the periodontal ligament and gingivae. [G. oxys, acid, + talas, suffering, resisting; coined term probably intended to mean "resistant to acid hydrolysis"]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxytetracycline oxytetracycline (ok´se-tet-ra-sI´klIn)
An antibiotic produced by the actinomycete, Streptomyces rimosus, present in the soil; its actions and uses are similar to those of tetracycline; available as the dihydrate, hydrochloride, and calcium.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxythiamin oxythiamin (ok-se-thI´a-min)
A molecule similar to that of thiamin but with a hydroxyl group replacing the amino group on the pyrimidine ring; a thiamin antagonist capable of inducing symptoms of thiamin deficiency on administration; increases thiamin excretion.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxytocia oxytocia (ok-se-to´se-a)
Rapid parturition. [G. okytokos, swift birth]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxytocic oxytocic (ok-se-to´sik)
1. Hastening childbirth. 2. parturifacient (2)



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxytocin (OXT) oxytocin (OXT) (ok-se-to´sin)
A nonapeptide neurohypophysial hormone, differing from human vasopressin in having leucine at position 8 and isoleucine at position 3, that causes myometrial contractions at term and promotes milk release during lactation; used for the induction or stimulation of labor, in the management of postpartum hemorrhage and atony, and to relieve painful breast engorgement.ocytocin; [G. okytokos, swift birth]
arginine o. o. with arginine at position 8 (identical with arginine vasotocin). See also arginine vasopressin.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyuriasis oxyuriasis (ok-se-yu-rI´a-sis)
Infection with nematode parasites of the genus Oxyuris.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyuricide oxyuricide (ok´se-yu´ri-sId)
An agent that destroys pinworms. [oxyurid + L. caedo, to kill]



Copyright© 1995 Williams & Wilkins. All rights reserved.

oxyurid oxyurid (ok-se-yu´rid)
Common name for members of the family Oxyuridae. [see Oxyuris]



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oxyuridae Oxyuridae (ok-se-yu´ri-de)
A family of parasitic nematodes (superfamily Oxyuroidea) found in the large intestine or cecum of vertebrates and the intestine of invertebrates, especially insects and millipedes; it includes the genera Aspiculurus, Enterobius, Oxyuris, Passalurus, Syphacia, and Thelandros.



Copyright© 1995 Williams & Wilkins. All rights reserved.

Oxyuris Oxyuris (ok´se-yu´ris)
A genus of nematodes commonly called seatworms or pinworms (although the pinworm of humans is the closely related form, Enterobius vermicularis). O. equi, the horse pinworm, is a common parasite of horses in all parts of the world, inhabiting the large intestine. [G. oxys, sharp, + oura, tail]



Copyright© 1995 Williams & Wilkins. All rights reserved.

-oyl -oyl
Suffix denoting an acyl radical; -yl replaces -ic in acid names.



Copyright© 1995 Williams & Wilkins. All rights reserved.

oz. oz.
Abbreviation for ounce.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozena ozena (o-ze´na)
A disease characterized by intranasal crusting, atrophy, and fetid odor. [G. ozaina, a fetid polypus, fr. ozo, to smell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozenous ozenous (o´ze-nus)
Relating to ozena.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozocerite ozocerite (o-zo-se´rIt)
ozokerite



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozochrotia ozochrotia (o-zo-kro´she-a)
bromidrosis [G. ozo, to smell, + chroa, skin]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozokerite ozokerite (o-zo-ker´It)
A mixture of paraffinic and cycloparaffinic hydrocarbons occurring in nature; it has a higher melting point than synthetic paraffin, and is used as a substitute for beeswax.ozocerite;
purified o. ceresin



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozonator ozonator (o´zo-na-ter, -tor)
An apparatus for generating ozone and diffusing it in the atmosphere of a room.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozone ozone (o´zon)
O3;a powerful oxidizing agent; air containing a perceptible amount of O3 formed by an electric discharge or by the slow combustion of phosphorus, and has an odor suggestive of Cl2 or SO2; also formed by the action of solar UV radiation on atmospheric O2. [G. ozo, to smell]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozonide ozonide (o´zo-nId)
The unstable intermediate formed by the reaction of ozone with an unsaturated organic compound, especially with unsaturated fatty acids.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozonolysis ozonolysis (o-zo-nol´I-sis)
The splitting of a double bond in a hydrocarbon chain upon treatment with ozone, with the formation of two aldehydes (an ozonide is the unstable intermediate); has been used to determine the structure of unsaturated fatty acids. [ozone + G. lysis, dissolution]



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozonometer ozonometer (o-zo-nom´e-ter)
A modified form of ozonoscope, in which by a series of test papers the amount of ozone in the atmosphere may be estimated.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozonoscope ozonoscope (o-zo´no-skop)
Filter paper saturated with starch and potassium iodide or with litmus and potassium iodide; turns blue in the presence of ozone.



Copyright© 1995 Williams & Wilkins. All rights reserved.

ozostomia ozostomia (o-zo-sto´me-a)
halitosis [G. ozo, to smell, + stoma, mouth]



Copyright© 1995 Williams & Wilkins. All rights reserved.