Peripheral Nerve

Question 1

Name each of the four functional components found in a peripheral nerve.

Answer 1

• Somatic Afferent (sensory)
• Somatic Efferent (motor)
• Visceral Afferent (sensory)
• Visceral Efferent (motor)
  
  • Preganglionic
  • Postganglionic

Question 2

what is innervated by somatic afferent component?

Answer 2

"muscle sensory"
pain
temperature
touch
conscious proprioception

Question 3

what is innervated by somatic efferent component?

Answer 3

“muscle motor”

striated muscle control

Question 4

what is innervated by visceral afferent component?

Answer 4

"organ sensory"
monitors internal environment
HR, BP
smooth muscle contractility
bladder and bowel fullness

Question 5

what is innervated by visceral efferent component?

Answer 5

“organ motor”
contraction of smooth muscle, peristalsis
secretion from glands

Question 6

identify the location of the preganglionic and postganglionic nerve cell bodies

Answer 6

Autonomic Efferent fibers

	- two neuron chain
	- Preganglionic cell body in CNS
	- Postganglionic cell body in autonomic ganglion

Question 7

list the functional components and target tissue of nerve fibers found in the posterior root and anterior root

Answer 7

Posterior root
-sensory/afferent fibers
Anterior root
-motor/efferent fibers

Question 8

List the functional components and target tissue of nerve fibers found in the posterior and anterior ramus.

Answer 8

Rami have both sensory/afferent and motor/efferent fibers

	- Posterior ramus serves posterior body (back)
	- Anterior ramus serves anterior body

Question 9

function and relative speed of conduction served by the A-alpha peripheral nerve fibers

Answer 9

speed- 70-120m/sec

function- myotatic reflex

Question 10

function and relative speed of conduction served by the A-beta peripheral nerve fibers

Answer 10

speed- 60-80m/sec

function- deep touch

Question 11

function and relative speed of conduction served by the A-delta peripheral nerve fibers

Answer 11

speed- 10-30m/sec

function- light touch, fast pain

Question 12

function and relative speed of conduction served by the C peripheral nerve fibers

Answer 12

speed- 0.5-2.5m/sec

function- slow pain

Question 13

List events seen during the degeneration and regeneration of a nerve fiber

Answer 13

Degeneration
if an axon is crushed, the axon distal to the crush will degenerate
the axon proximal to the crush will die back a short distance
the cell body will respond by becoming more metabolically active (chromatolysis)
axon and myelin degenerate (but not Schwann cells)
macrophage cells engulf debris
Regeneration
axons sprout and exhibit growth cones
schwann cells undergo mitosis and form guiding route for growth cone