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12 Cards in this Set
- Front
- Back
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where does excitation occur? |
Neuromuscular Juntion |
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Arrange these steps of exocytosis in order (1st - 5th) |
(1) action potential arrives at axon terminal of motor neuron (2) voltage gates Ca2+ channles open and it enters the axon terminal moving down its eltrochemical gradient (3) Ca2+ enry causes ACh (acetylcholine) to be realsease by exocytosis (4) ACh difussrs across the synaptic cleft and binds to ita receptors on the sarcolema (5) ACh binding opens ion channels in the receptors that allow Na+ in and K+ out the muscke fiber simountaneously. |
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label the missing parts of the graph |
A- Na+ B- Depoalrization C- Na+ D- K+ E- Repolarization F- K+ |
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NMJ |
neuromuscular junction |
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what occurs during Excitation Contraction (EC) Coupling? |
AP spreads in all direction of the NMJ along the sarcolemma and travels down the T-tubles into the interior of the muscle cell |
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arange the steps of EC coupling in the correct order |
(1) Action potential is propagated along the sarcolemma and down the T tubules (2) Calcium ions are released
(3) calcium binds to troponin and remoces the blocking action of tropomyosin (4) contraction begins |
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SR |
sarcoplasmic reticulum |
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calcium released by the SR binds to? |
Troponin |
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Troponin-tropomyosin complex changes shape and exposes ________ on _______filaments |
active sites; actin |
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these are the steps of? |
contraction |
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arrange the steps of contraction in the correct order. |
(1) cross bridge formation: energized myosin head attches to an actin myofilament (2) the power (working stroke): ADP and Pi are released and the myosin head pivots and bends changing its bent low-energy state. (3) Cross bridge detachment: ATP attaches to myosin, link between myosin and actin weakens, myosin head detaches (the cross bridge "breaks") (4) Cocking of myosin head: ATP is hydrolyzed to ADP and P the myson head returns to its prestroke or "cocked" position |
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in the abscence of ATP during the contraction cycle, mysoin heads will not detach causing? |
Rigor motis |
