Reactions of Neurons to Injury

Question 1

what are the nerve sheaths

Answer 1

epineurium
perineurium
endoneurium

Question 2

structure of epineurium

Answer 2

dense connective tissue that
surrounds a nerve trunk

Question 3

structure of perineurium

Answer 3

connective tissue that surrounds
nerve bundles

Question 4

structure of endoneurium

Answer 4

loss, delicate connective tissue
surrounding individual nerve fibers

Question 5

what are the mechanisms of peripheral nerve injury

Answer 5

laceration, compression and stretch

Question 6

what is wallerian degeneration

Answer 6

changes in axon’s myelin sheath distal to the site of severance

Question 7

discuss the process of wallerian degen

Answer 7

Breakdown of axon, Schwann cells reject the myelin portion of their membranes, macrophages, migrate and remove degenerated axons and myelin

Question 8

if an axon is severed or crushed what reactions are seen in the nucleus

Answer 8

Cell swelling including nucleus and nucleolus; nucleus moves from central position to the periphery

Question 8

if an axon is severed or crushed what reactions are seen in the nissl body

Answer 8

Nissl bodies undergo chromatolysis

Question 9

if an axon is severed or crushed what reactions are seen in the cell body

Answer 9

must synthesize new mRNA, lipids and cytoskeletal proteins

Question 10

what carries the synthesized mRNA, lipids and cytoskeletal proteins

Answer 10

carried by slow anterograde axonal transport at rate of 5-6mm/day,