Integration-Neuromuscular Flashcards Preview

MSK I > Integration-Neuromuscular > Flashcards

Flashcards in Integration-Neuromuscular Deck (9)
1

What causes the degenerative effects of multiple sclerosis?

Immune-mediated inflammation, destruction of myelin and consequential axon loss

2

What virus has been found to kick-off multiple sclerosis?

Epstein-Barr virus. It may initiate the inflammatory response that activates chronic inflammatory cells (activated macrophages) that cause degeneration of neurons.

3

What drug is prescribed as a result of demyelination of axons?

Dalfampridine. It blocks the exposed K+ channels that were originally covered by the myelin sheath.

4

How do astrocyte defects cause the effects of multiple sclerosis?

Glutamate pump is defected and levels build up near the axon and damage the myelin sheath.

5

How can you help nerves to remyelinate after axon damage?

Oligo precursor cells proliferate and migrate to demyelinated axons. Mature oligodendrocytes do not repair.

6

What happens to axons after a nerve is cut in the CNS?

They degenerate and are eaten up by macrophages.

7

What happens to axons after a nerve is cut in the PNS?

Schwann cells lay down a pathway for regeneration in an area cleared by macrophages.

8

What is your goal when doing a nerve graft?

Clear a pathway for the axon to grow down back to its original place.

9

What happens to muscle if innervation is impaired?

Atrophy and a change from glycolytic fibers (type II) to oxidative fibers (type I).