Peripheral Nervous System: pgs 11-16

Question 1

What is a collection of cell bodies and its attached axons?

Answer 1

ganglia

Question 2

What is a collection of axons wiht no cell bodies?

Answer 2

Nerves

Question 3

Preganglionic axons are __(short/long)__ in relation to the postganglionic axons in the SNS?

Answer 3

Short

Question 4

Preganglionic axons are __(short/long)__ in relation to the postganglionic axons in the PNS?

Answer 4

Long

Question 5

What is a motor unit?

Answer 5

A lower motor neuron and all the muscle fibers it innervates

Question 6

What happens when an axon is cut and separated from its cell body?

Answer 6

The cell body swells, the nucleus goes to the side, and the Nissl substance and ribosomes are no longer visible (chromatolysis).

Question 7

The separated portion of a cut axon, known as the distal segment undergoes _______________ degeneration, in which the axon and myelin fragments are removed by macrophages.

Answer 7

Wallerian

Question 8

What cells help to clean up the mess of axonal degenerated portions and produces factors to facilitate regeneration in the PNS?

Answer 8

Schwann cells

Question 9

T/F- Peripheral nerves are mixed in function.

Answer 9

True - They contain a variable number of sensory fibers carrying information back to the CNS and LMN fibers going to skeletal muscle. Visceromotor (autonomic) fibers may also be present

Question 10

Newly sprouted axons are directed by guidance tubes formed by __________ cells.

Answer 10

Schwann

Question 11

What is the functional rate of regeneration?

Answer 11

1.5 mm per day

Question 12

What are the different layers of CT wrappings?

Answer 12

Epineurium, perineurium, and then endoneurium (order from outside inward)