1. 19 October 2009 This Week in Physiology:
Wednesday Quiz: Cranial Nerves
Lab: Sensory Physiology &
Auditory System
Lectures: Ch. 9 Muscle Physiology
Approaching Fall Break!

4. Different types of muscles for different tasks!
Characteristics: Location, cell shape, nuclei per cell, innervation, arrangement of actin and myosin, regulation of cross bridges, sources of Ca++, etc.
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Different types of muscles for different tasks!

6. NMJ = neuromuscular junction Myoneural junction Motor end plate
Fig
Synonyms:
NMJ = neuromuscular junction
Myoneural junction
Motor end plate
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7. 1 AP in motor axon releases sufficient ACh for 1 AP in skeletal muscle
Fig
1 AP in motor axon releases sufficient ACh for 1 AP in skeletal muscle
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Nicotinic

8. Fig
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9. How does AP in sarcolemma cause twitch???
Fig a
Capillaries
???
How does AP in sarcolemma cause twitch???
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10. Terms: Myofiber, myofibril, myofilament
Fig b
Terms: Myofiber, myofibril, myofilament
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Thick myofilament = myosin Thin myofilament = actin

11. Fig a
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12. Fig
The concentration of free calcium is directly related to force of contraction in skeletal muscle
Thus we need to understand the cellular mechanism of contraction… cell biology flashbacks…
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13. dArk band = aligned myosin filaments
Fig
dArk band = aligned myosin filaments
lIght band = absence of myosin filaments
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15. Fig
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16. Fig
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17. Fig a
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18. Fig b
Contracted
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19. Fig
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20. Fig
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21. Energy for powerstroke & Necessary for detaching myosin from actin
Fig
2 roles of ATP:
Energy for powerstroke &
Necessary for detaching myosin from actin
Crossbridge cycling continues as long as ATP and Ca++ present.
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22. Fig
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23. Muscle kinetics
Link to cytosolic calcium concentration, release, and reuptake?
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