Rxn to Injury

Question 1

How are PNS nerve fibers different from CNS nerve fibers?

Answer 1

PNS nerve fibers can regerate

Question 2

What is distal axonal degeneration? In what type of neuropathies does this type of axonal degeneration occur?

Answer 2

The distal end of larger neurons degenerate but the neuronal cell bodies and proximal axons remain intact; Dying-back neuropathies

Question 3

What is a neuronopathy? What is the prognosis?

Answer 3

Death off the neuronal cell body; Little potential for recovery

Question 4

When does Wallerian Degeneration occur? Prognosis?

Answer 4

Axonal degeneration that occurs in a nerve distal to a transection or crush injury; If injury not too proximal, nerve may regenerate

Question 5

What causes primary demyelination?

Answer 5

Injury to Schwann Cell or myelin sheath.

Question 6

What causes secondary demyelination?

Answer 6

Underlying axonal abnormalities

Question 7

What are the results of repeated segmental demyelination?

Answer 7

Accumulation of supernumerary Schwann cells around axons (onion bulbs) and hypertrophic neuropathy