Top 550+ Solved Physiology MCQ Questions Answer

a. it is an active, self-propagating process

b. salutatory conduction occurs in unmyelinated neurons

c. axons can conduct impulses in either direction

d. conduction velocity is proportional to nerve fibre diameter

e. “current sink” occurs in neuronal cell membrane ahead of impulse

a. proprioception

b. preganglionic autonomic

c. temperature

d. postganglionic sympathetic

e. somatic motor

a. resting membrane potential is about -90mV

b. action potentials are generated at the initial segment in spinal motor neurons

c. myelin produces up to 50 times faster conduction of impulses

d. membrane is more permeable to potassium than sodium at rest

e. sodium channels are highly concentrated at the nodes of ranvier

a. resting membrane potential is about -90mV

b. resting length is the length at which active tension in the muscle is maximal

c. total glycogen stored is about 0.4kg

d. energy source at rest is mainly glucose

e. resting heat production is due to basal metabolic processes

a. A-alpha

b. A-beta

c. A-gamma

d. B

e. C

a. proprioception

b. pain

c. pressure

d. touch

e. motor to muscle spindles

a. do not have Schwann cells associated with them

b. display salutatory conduction

c. constitute most of the cell population in the human central nervous system

d. do not occur in humans

e. none of the above are true

a. thick filaments which are made up of myosin and tropomyosin are lined up to form A bands

b. the dark A band has a light H band in its centre which in turn has an M line in its middle

c. think filaments are made up of actin, tropomyosin and troponin and form the H band

d. Z lines are connected to the thick filaments

e. during contraction, the width of the A band reduces

a. conduct proprioception

b. are amongst the largest of the nerve fibres

c. are the fibres most susceptible to hypoxia

d. administration of lignocaine suppresses transmission in C fibres before affecting A fibres

e. are myelinated

a. only occurs in myelinated neurons

b. is slower than non-saltatory conduction

c. is unaffected by local anaesthetics

d. does not occur with anti-dromic conduction

e. is directly proportional in rate to the size of the action potential

a. a flexor muscle and an extensor muscle

b. a single skeletal muscle and all the motor neurons that supply it

c. a single motor neuron and all the muscle fibres it innervates

d. a large bundle of muscle fibres

e. all the motor neurons in which responses are observed after maximal stimulation

a. by binding troponin C it uncovers the binding site of actin to interact with the myosin head

b. by binding troponin I, it uncovers the binding site of actin to interact with the myosin head

c. by binding to tropomyosin, it allows troponic to bind to myosin

d. by binding to troponin C, it allows the myosin head to disengage resulting in relaxation

e. it causes depolarisation to spread along the tubules

a. makes the resting membrane more negative in nerve cells

b. causes a similar effect in nerve cells as a decrease in extracellular Na+

c. has little effect in nerve cell membrane potential

d. may decrease nerve cell action potential size

e. cause a similar effect in nerve cells as an increase in extracellular Ca++

a. occurs because of the short refractory period of skeletal muscle

b. is due to increased calcium available for binding to troponin C

c. enables a tension development of approximately four times that of individual twitch contraction

d. occurs only with isometric contractions

e. has the same mechanism of that of cardiac muscle

a. Ca2+ for contraction is released from sarcoplasmic reticulum

b. membrane potential has a resting value of -90mV

c. the excitation contraction coupling time is rapid (<10ms)

d. muscle contracts when stretched in absence of innervation

e. binding of acetylcholine to nicotine receptors increases Ca2+ influx