{calcitonin}{}{Hormone released from parafollicular cells that acts on tissues to cause a decrease in blood levels of calcium ions.}

{canaliculus [canaliculi]}{}{Microscopic canal that connects lacunae of bone tissue.}

{cancer}{}{General term frequently used to indicate any of various types of malignant neoplasms, most of which invade surrounding tissues, may metastasize to several sites, and are likely to recur after attempted removal and to cause death of the patient unless adequately treated.}

{carbohydrate}{}{Monosaccharide [simple sugar] or the organic molecules composed of monosaccharides bound together by chemical bonds, e.g., glycogen. For each carbon atom in the molecule there is typically one oxygen molecule and two hydrogen molecules.}

{cardiac muscle}{}{Specialized muscle tissue found only in the heart.}

{catalyst}{}{Substance that increases the rate at which a chemical reaction proceeds without being changed permanently.}

{caudal}{}{Pertaining to the tail end of the body.}

{cecum}{}{The junction of the small and large intestines.}

{cell}{}{Smallest living structural and functional unit of an organism.}

{cellular respiration}{}{Cellular process that releases energy from organic compounds.}

{central canal}{}{Tube within spinal cord that is continuous with brain ventricles and contains cerebrospinal fluid.}

{central nervous system [CNS]}{}{Major subdivision of the nervous system consisting of the brain and spinal cord.}

{central sulcus}{}{A groove in the lateral portion of the cerebrum that runs from superior to inferior.}

{centriole}{}{Cellular organelle built of microtubules that organizes mitotic spindle.}

{cephalic}{}{Pertaining to the head.}

{cerebellum}{}{Separate portion of the brain attached to the brainstem at the pons; important in maintaining muscle tone, balance, and coordination of movement.}

{cerebrospinal fluid [CSF]}{}{Fluid filling the ventricles and surrounding the brain and spinal cord.}

{cerebrum}{}{Portion of brain that occupies upper part of cranial cavity and provides higher mental functions.}

{cervix}{}{Narrow, inferior "neck" of uterus that leads into vagina.}

{chemical}{}{Formed from interactions between and among atoms and the formation of molecules.}

{chemoreceptors}{}{Sensory cell that is stimulated by a change in the concentration of chemicals to produce action potentials. Examples include taste receptors, olfactory receptors, and carotid bodies.}

{chondrocyte}{}{Mature cartilage cell.}

{chorionic villus [villi]}{}{A projection that extends from the outer surface of the chorion and helps attach the embryo to the uterine wall.}

{chromatid}{}{One half of a chromosome; separates from its partner during cell division.}

{chromatin}{}{Colored material; the genetic material in the nucleus.}

{chromosome}{}{Colored body in the nucleus, composed of DNA and proteins and containing the primary genetic information of the cell; 23 pairs in humans.}

{chyme}{}{Semifluid mass of partially digested food that passes from stomach to small intestine.}

{cilium [cilia]}{}{Microscopic, hairlike process on exposed surfaces of certain epithelial cells.}

{circulation}{}{Path of blood through system of vessels.}

{circumduction}{}{Movement in a circular motion.}

{circumvallate papilla [papillae]}{}{Type of papilla on the surface of the tongue surrounded by a groove.}

{citric acid cycle}{}{Series of chemical reactions in which citric acid is converted into oxaloacetic acid, carbon dioxide is formed, and energy is released. The oxaloacetic acid can combine with acetyl-CoA to form citric acid and restart the cycle. The energy released is used to form NADH, FADH, and ATP.}

{cleavage}{}{Early successive divisions of blastocyst cells into smaller and smaller cells.}

{clitoris}{}{Small, erectile organ in anterior of vulva; corresponding to penis.}

{codon}{}{Sequence of three nucleotides in mRNA or DNA that codes for a specific amino acid in a protein.}

{coelom}{}{Space that develops within the mesoderm of the developing embryo.}

{collagenous fiber}{}{Proteinaceous white fibers of connective tissues and bone matrix.}

{collecting duct}{}{Tube receiving renal filtrate from distal convoluted tubule.}

{columnar cell}{}{Cell shaped like a column.}

{common bile duct}{}{Tube that transports bile from cystic duct to duodenum.}

{common hepatic duct}{}{Duct formed from the combined hepatic ducts from the liver lobes.}

{concentration gradient}{}{The area between two compartments of a solution that contains solutes in different concentrations}

{condensation [dehydration] reaction}{}{A chemical reaction that unites two molecules into one.}

{connective tissue}{}{One of the basic types of tissue that includes bone, cartilage, and loose and fibrous connective tissue.}

{contractility}{}{The ability to contract or make shorter.}

{contralateral}{}{On opposite sides of the body.}

{control center}{}{A key component of negative feedback systems that determines the set point of a physiological state.}

{convergent pathway}{}{Nerve impulses arriving at the same neuron.}

{coronal plane}{}{A plane that separates the body into anterior and posterior portions; also called a frontal plane.}

{covalent bond}{}{Chemical bond characterized by the sharing of electrons.}

{cranial nerve}{}{Nerve that originates from a nucleus within the brain; there are 12 pairs of cranial nerves.}

{cranial vault}{}{Eight skull bones that surround and protect the brain; brain case.}

{cribriform plate}{}{Portion of the ethmoid bone through which olfactory nerves extend.}

{cross bridge}{}{Bond formed between actin and myosin during muscle contraction.}

{cross-sectional plane}{}{A plane that divides the body into superior and inferior portions; also called a transverse plane.}

{cuboidal cell}{}{A cell that resembles a cube.}

{cystic duct}{}{Tube that connects the gallbladder to the common bile duct.}

{cytokinesis}{}{Division of the cytoplasm during cell division.}

{cytoplasm}{}{Contents of a cell, excluding the nucleus and cell membrane.}

{cytoplasmic inclusion}{}{Any foreign or other substance contained in the cytoplasm of a cell.}

{cytosine}{}{One of four nucleotides found in DNA and RNA; abbreviated as "C."}

{cytoskeleton}{}{Consists of protein fibers that extend through the cytoplasm of a eukaryotic cell to provide structure, support, and movement.}

{cytosol}{}{Contents of a cell, excluding the nucleus and cell membrane.}