PHYSIOLOGY
SKELETAL MUSCLE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Which of these events must occur first to trigger the skeletal muscle to generate an action potential and contract:
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acetylcholine (ACh) causes temporary permeability to sodium
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acetylcholinesterase (AchE) breaks down acetylcholine (ACh)
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operation of the sodium-potassium pump
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diffusion of potassium ions out of the cell
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Explanation:
Detailed explanation-1: -The first step in the process of contraction is for Ca++ to bind to troponin so that tropomyosin can slide away from the binding sites on the actin strands. This allows the myosin heads to bind to these exposed binding sites and form cross-bridges.
Detailed explanation-2: -Depolarisation and calcium ion release. Actin and myosin cross-bridge formation. Sliding mechanism of actin and myosin filaments. Sarcomere shortening (muscle contraction)
There is 1 question to complete.