home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
ftptest.leeds.ac.uk
/
2015.02.ftptest.leeds.ac.uk.tar
/
ftptest.leeds.ac.uk
/
bionet
/
mcq_etc
/
phys_mcq.exe
/
PNERVE.MCQ
< prev
next >
Wrap
Text File
|
1993-08-06
|
6KB
|
222 lines
D:Created 14.49 06/08/1993
D:Subject : Physiology
D:Topic : Peripheral nerve
D:Level : Moderate
D:
D:Authors : Department of Physiology
D: The University
D: Leeds LS2 9NQ
I:MCQ SB 1
G:3
G:1:Dental Students
Q:1,2,4,7,9,10
G:2:Medical Students
Q:1,2,4,7,9,10
G:3:Science Students
Q:1,2,4,7,9,10
T:A
L:2
#:1
G: 1 2 3
S:1
:The resting potential across the nerve membrane:
B:N:5
B:1:T:2
:depends on the ratio of the potassium concentrations inside and
:outside the cell
B:2:F:1
:is positive inside with respect to outside
B:3:F:1
:is of the order of 0.1 volt
B:4:T:1
:decreases in magnitude during prolonged anoxia
B:5:F:1
:is greater the larger the diameter of the fibre
F:1
:No explanation available.
E:------
#:2
G: 1 2 3
S:1
:The resting potential across the nerve membrane:
B:N:5
B:1:T:2
:is proportional to log intracellular [K] for small changes of
:extracellular [K]
B:2:F:1
:is greater the larger diameter of the fibre
B:3:T:1
:is greater inside with respect to outside
B:4:T:1
:is about 0.07 to 0.09v
B:5:F:1
:increases during metabolic blockade
F:1
:No explanation available.
E:------
#:3
G: 10464 10464 10464 10464 10464 10464 10464 10464 10464 10464
S:1
:n velocity:
B:N:5
B:1:F:1
:is greater in group C nerve fibres than in group A nerve fibres
B:2:T:2
:is greater in large diameter nerve fibres than in small diameter
:fibres
B:3:F:1
:is greatest in unmyelinated nerve fibres
B:4:T:1
:can be as fast as 120 meters per second in human nerve fibres
B:5:T:1
:is decreased by a decrease of temperature
F:1
:No explanation available.
E:------
#:4
G: 1 2 3
S:1
:When you recorded the action potential of the frog sciatic nerve:
B:N:5
B:1:F:2
:the magnitude (amplitude) of the action potential was independent of
:stimulus strength
B:2:F:2
:stimulus strength could be altered only by changing the voltage
:applied to the stimulating electrode
B:3:T:2
:the stimulus was used to start the oscilloscope beam "sweep" before
:a stimulus was applied to the nerve
B:4:T:1
:the nerve could conduct impulses in both directions
B:5:T:2
:an oscilloscope was used because of its ability to respond to rapid
:voltage changes
F:1
:No explanation available.
E:------
#:5
G: 10464 10464 10464 10464 10464 10464 10464 10464 10464 10464
S:1
:ation of a nerve impulse:
B:N:5
B:1:F:1
:depends on local currents that flow in through the cell membrane
B:2:F:1
:is by saltatory conduction in non-myelinated axons
B:3:T:1
:occurs at a higher velocity in axons of larger diameter
B:4:T:1
:is possible at speeds exceeding 100 m per s
B:5:T:1
:cannot occur unless the fluid bathing the axon contains sodium ions
F:1
:No explanation available.
E:------
#:6
G: 10464 10464 10464 10464 10464 10464 10464 10464 10464 10464
S:1
:er diameter, myelinated cutaneous sensory axons:
B:N:5
B:1:F:1
:have their cell bodies in the dorsal horn
B:2:F:1
:have a conduction velocity of 2 m per s
B:3:T:1
:form synaptic connections on interneurones in the spinal cord
B:4:F:2
:have branches which cross in the spinal cord and form the dorsal
:columns
B:5:T:1
:contribute an input to the contralateral spinothalamic tract
F:1
:No explanation available.
E:------
#:7
G: 10464 1 2 3
S:1
:Sensory axons with endings in the dentine:
B:N:5
B:1:T:1
:have their cell bodies in the trigeminal ganglion
B:2:F:1
:form monosynaptic connections onto alpha motor neurones
B:3:T:1
:are excited by fluid flow in the dentinal tubules
B:4:F:1
:are inhibited by local cooling of the tooth surface
B:5:T:2
:have action potentials that may be blocked by the injection of local
:anaesthetic
F:1
:No explanation available.
E:------
#:8
G: 10464 10464 10464 10464 10464 10464 10464 10464 10464 10464
S:2
:wing electrophysiological changes occur in carpal tunnel
:syndrome:
B:N:5
B:1:F:1
:large amplitude sensory action potential
B:2:T:1
:increased latency of sensory action potential
B:3:F:1
:a decreased conduction velocity in the median nerve in the forearm
B:4:T:1
:increased distal motor terminal latency in the median nerve
B:5:F:1
:wasting of forearm muscles
F:5
:Electro-physiological measurements on nerves and muscles above the
:wrist are normal in carpal tunnel syndrome. Abnormalities, such as a
:prolonged distal motor terminal latency, and a reduction in the sensory
:conduction velocity distal to the wrist are common in carpal tunnel
:syndrome. These changes can occur in any nerve that is compressed.
E:------
#:9
G: 10464 1 2 3
S:2
:A propagating action potential in a 250 micrometer diameter
:squid giant axon:
B:N:5
B:1:F:1
:has a depolarisation phase that extends over about 20 ms of axon.
B:2:T:1
:has an after hyperpolarisation that lasts about 20 ms.
B:3:T:1
:has a conduction velocity of about 20 m per s
B:4:F:2
:has an axial current that is much greater than the total membrane
:current
B:5:F:2
:has a capacitative current density that is equal and opposite to the
:membrane ionic current density
F:1
:No explanation available.
E:------
#:10
G: 10464 1 2 3
S:2
:An isopotential preparation of a squid giant axon is voltage-
:clamped by a depolarization of 40 mV from its resting membrane potential:
B:N:5
B:1:F:2
:increasing the sodium concentration of the extracellular medium
:would increase the sodium conductance
B:2:F:2
:increasing the sodium concentration of the extracellular medium
:would decrease the maintained outward current
B:3:T:2
:decreasing the calcium concentration of the extracellular medium
:would increase the inward current
B:4:F:2
:addition of microM concentrations of tetrodotoxin would slow the
:change in inward conductance
B:5:F:1
:the inward current density would be of the order of mA per sq cm.
F:1
:No explanation available.
E:------
::