PHYSIOLOGY
SKELETAL MUSCLE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Once started, the action potential cannot be stopped, and contraction occurs
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True
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False
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Either A or B
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None of the above
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Explanation:
Detailed explanation-1: -The falling phase of the action potential is caused by the inactivation of the sodium channels and the opening of the potassium channels. After approximately 1 msec, the sodium channels inactivate. The channel becomes blocked, preventing ion flow.
Detailed explanation-2: -The action potential invades T-tubules and causes the L-type calcium channels to open, which in turn causes ryanodine receptors (RyRs) in the SR to open and release calcium, which stimulates contraction.
There is 1 question to complete.