Nervous System

Question 1

A 45 years old woman who works in an office had been experiencing tingling in her index and middle fingers and thumb of her R hand. Recently, her wrist and hand had become weak. Her physician ordered a nerve conduction test to evaluate her carpal tunnel syndrome. Which one of the following nerves has the slowest conduction velocity?

A. A alpha fibers
B. A beta fibers
C. A y fibers
D. B fibers
E. C fibers

Answer 1

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Question 2

A man falls into a deep sleep with one arm under his head. This arm is paralyzed when he awakens, but it tingles, and pain sensation in it is still intact. The reason for the loss of motor function without loss of pain sensation is:

A. A fibers are more susceptible to hypoxia than B fibers
B. A fibers are more sensitive to pressure than C fibers
C. C fibers are more sensitive to pressure than A fibers
D. Motor nerves are more affected by sleep than sensory nerves
E. Sensory nerves are nearer the bone than motor nerves and hence are less affected by pressure.

Answer 2

B. A fibers are more semsitive to pressure than C fibers

Question 3

A precocious 6 year old girl asked her aunt who was a neurologist at a local medical school to explain how a neuron works. Her aunt explained how different parts of the neuron have a specific role in generating and transmitting an action potential. She identified the part of the neuron where the action potential is iniated, a part that receives input from other neurons, and a part that conducts the action potential. These would have been as follows:

A. Soma, dendrite, axon
B. Axon hillock, soma, myelin sheath
C. Cell membrane, soma , dendrite
D. Initial segement, dendrite, axon
E. Axon hillock, soma, myelin sheath

Answer 3

D. Initial segment, dendrite, axon