Peripheral nerve and Skeletal Flashcards
(21 cards)
Axon and myelin sheath undergoes anterograde degeneration
Axonal degeneration
Random myelin internodes are injured and remyelinated by multiple schwann cells, axon and myocytes are intact.
Segmental demyelination
Sprouting of adjacent uninjured motor axons leads to myocyte fiber type grouping.
Reinnervation
Scattered myocytes of different motor units are small while the neurons and nerve fibers are normal.
Myopathy
Determine the type of muscle fiber types:
Action: sustained force
Type 1
Determine the type of muscle fiber types:
Action: sudden movement
Type 2
Determine the type of muscle fiber types:
Strength: purposeful motion
Type 2
Determine the type of muscle fiber types:
Strength: weight bearing
Type 1
Determine the type of muscle fiber types: Enzyme content: NADH dark staining ATPase pH 4.2 dark staining ATPase pH 9.4 light staining
Type 1
Determine the type of muscle fiber types: Enzyme content: NADH light staining ATPase pH 4.2 light staining ATPase pH 9.4 dark staining
Type 2
Determine the type of muscle fiber types:
Lipids: abundant
Type 1
Determine the type of muscle fiber types:
Lipids: scant
Type 2
Determine the type of muscle fiber types:
Glycogen: scant
Type 1
Determine the type of muscle fiber types:
Glycogen: abundant
Type 2
Determine the type of muscle fiber types:
Ultrastructure: many mitochondria with wide z-band
Type 1
Determine the type of muscle fiber types:
Ultrastructure: few mitochondria with narrow z band
Type 2
Determine the type of muscle fiber types:
Physiology: slow twitch
Type 1
Determine the type of muscle fiber types:
Physiology: fast twitch
Type 2
Determine the type of muscle fiber types:
Color: red
Type 1
Determine the type of muscle fiber types:
Color: white
Type 2
This is caused by schwan cells dysfunction or primary myelin sheath damage, the underlying axon is normal.
Myelin loss in segmental demyelination
