13. The Peripheral Nervous System

A spinal nerve divides into a(n)_____ that serves the anterior side of the body and the limbs and a(n)_____that serves the posterior side of the body.

Mary complains that when she wakes up in the morning, her thumb and forefinger are always “asleep.” She mentions this condition to her physician, who asks Mary whether she sleeps with her wrists flexed. She replies that she does. The physician tells Mary that sleeping in that position may compress a portion of one of her peripheral nerves, producing her symptoms. Which nerve is involved?

A sensory region monitored by the posterior rami of a single spinal segment is

(a) A ganglion

(b) A fascicle

(c) A dermatome

(d) A ramus

Define each of the following terms in your own words, using 20 or fewer words.

a. Peripheral nerve

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

e. There are 31 pairs of spinal nerves and 12 pairs of cranial nerves.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

d. The term nerve is the equivalent of the term neuron.

Spinal nerves are called mixed nerves because they

(a) Contain sensory and motor fibers

(b) Exit at intervertebral foramina

(c) Are associated with a pair of spinal ganglia

(d) Are associated with posterior and anterior roots

Joseph, a man in his early 70s, was having problems chewing his food. He was asked to stick out his tongue. It deviated to the right, and its right side was quite wasted. What cranial nerve was impaired?

Which cranial nerves are (a) sensory only, (b) primarily motor, and (c) mixed?

How many pairs of cranial nerves are there? Which are purely sensory? Which activates the chewing muscles? Which helps regulate heart rate and activity of the digestive tract?

The major nerve of the cervical plexus that innervates the diaphragm is the

(a) Median nerve

(b) Axillary nerve

(c) Phrenic nerve

(d) Common fibular nerve