PHYSIOLOGY
MUSCLE CONTRACTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Sarcolemma
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T Tubules
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Sarcoplasmic Reticulum
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Calcium Channel
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Detailed explanation-1: -The action potential travels down the t-tubules and excites the sarcoplasmic reticulum which releases calcium. Calcium when bound to troponin causes conformational changes in the sarcomere. Consequently, the interaction of thick and thin filaments of the sarcomere leads to muscle contraction.
Detailed explanation-2: -The function of T-TUBULES is to conduct impulses from the surface of the cell (SARCOLEMMA) down into the cell and, specifically, to another structure in the cell called the SARCOPLASMIC RETICULUM.
Detailed explanation-3: -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. Calcium is pumped back into the SR by (SR/ER calcium ATPase SERCA) pumps.