Organization of the Peripheral Nervous System

Question 1

Functional Subdivisions of PNS:

Answer 1

Somatic-composed of neural elements associated with the body wall and extremities
Autonomic-composed of neural elements associated with the internal organs or viscera
*both transmit afferent and efferent information

Question 2

Components of PNS:

Ganglia

Answer 2

-ovoid structures containing neuronal cell bodies and glial cells supported by CT

Question 3

Ganglia Types (2):

Answer 3

• Sensory (Somatic & Visceral)-associated with the dorsal roots of spinal nerves and cranial nerves 5, 7, 8, 9, & 10; contain the cell bodies of pseudounipolar neurons
• Motor (Visceral)-sympathetic and parasympathetic

Question 4

Components of PNS:

Nerves

Answer 4

-a nerve fiber consists of an axon and its investing Schwann cells

Question 5

Nerve Classification:

Answer 5

• Spinal (31 pairs): can be GSE, GVE, GSA, GVA

- Cranial (12 pairs): can be GSE, GVE, SVE, GSA, GVA, SSA

Question 6

Surface Coverings (or CT sheaths) of Neurons (3):

Answer 6

1. Epineurium: sheath of dense CT that surrounds the entire nerve
2. Perineurium: sheath of dense CT that surrounds bundles of nerve fibers, called fascicles
3. Endoneurium: sheath of loose CT that surrounds the individual nerve fibers