1.3 Major Divisions of PNS

12 pairs

Number of cranial nerves

31 pairs

Number of spinal nerves

8

Number of cervical nerves

12

Number of thoracic nerves

5

Number of lumbar nerves

5

Number of sacral nerves

1

Number of coccygeal nerves

efferent fibers

The anterior root consists of bundles of nerve fibers carrying nerve impulses away from the CNS________

motor fibers

Those that go to skeletal muscles and cause them to contract are ________

Afferent fibers

carry nervous impulses to the CNS

sensory fibers

these fibers convey information about sensations of touch, pain, temperature, and vibration, they are called

posterior root ganglion

The cell bodies of these nerve fibers are situated in a swelling on the posterior root called the _________.

Sensory Ganglia

are fusiform swellings on the posterior root of each spinal nerve just proximal to the root’s junction with a corresponding anterior root.

Autonomic ganglia

Are often irregular in shape, are situated along the course of efferent nerve fibers of the ANS.