13. The Peripheral Nervous System

Why is visceral pain often perceived as cutaneous pain?

How do upper and lower motor neurons differ?

List and describe the basic steps involved in producing movement, beginning with the upper motor neurons in the cerebral cortex.

The lower motor neurons that innervate contractile skeletal muscle fibers are called:

a. α-motor neurons

b. β-motor neurons

c. upper motor neurons

d. γ-motor neurons

Explain why you lose both motor and sensory function of a part of your body when a spinal nerve is numbed with anesthetic agents.

When Mr. Williams goes to the emergency department with pain in the area along the midline of the diaphragm, he worries he is having a heart attack. Could the pain be related to his heart? Could it be related to any other organ(s)? Explain.

What are the three major somatic sensory pathways and their functions?

Ramin presents for evaluation after a severe shoulder injury during which his entire brachial plexus suffered damage. What effects would you expect Ramin to have from this injury?

When Mr. Dinh goes to the emergency department with pain in the area along the midline of the diaphragm, he worries he is having a heart attack. Could the pain be related to his heart? Could it be related to any other organ(s)? Explain.

Briefly describe the three stages of neuron development.

The neural machinery of the spinal cord is at the

(a) precommand level

(b) projection level

(c) segmental level

For each of the following muscles or body regions, identify the plexus and the peripheral nerve(s) (or branch of one) involved. Use choices from keys A and B.

 ___; ___ (1) the diaphragm

___; ___ (2) muscles of the posterior leg

 ___; ___ (3) anterior thigh muscles

 ___; ___ (4) medial thigh muscles

 ___; ___ (5) anterior arm muscles that flex the forearm

 ___; ___ (6) muscles that flex the hand and digits (two nerves)

 ___; ___ (7) muscles that extend the hand and digits

 ___; ___ (8) skin and extensor muscles of the posterior arm

 ___; ___ (9) fibularis muscles, tibialis anterior, and toe extensors

___; ___, ___, ___, (10) elbow joint

Key A: Plexuses

(a) brachial

(b) cervical

(c) lumbar

(d) sacral

Key B: Nerves

(1) common fibular

(2) femoral

(3) median

(4) musculocutaneous

(5) obturator

(6) phrenic

(7) radial

(8) tibial

(9) ulnar