PHYSIOLOGY
SKELETAL MUSCLE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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excess ATP is stored in the tubules
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calcium ions are released into tubules’ extracellular fluid
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action potentials are conducted through the tubules to the inside of the cell
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ATP is produced in the mitochondria found in the tubules
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Detailed explanation-1: -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.
Detailed explanation-2: -The transverse tubules (T-tubules) of mammalian cardiac and skeletal muscles are invaginations of the sarcolemma. They play a crucial role in excitation-contraction coupling as well as in intracellular signaling and in regulation of glucose transport.
Detailed explanation-3: -The transverse tubules (t-tubules) are invaginations of the cell membrane rich in several ion channels and other proteins devoted to the critical task of excitation–contraction coupling in cardiac muscle cells (cardiomyocytes).
Detailed explanation-4: -The correct answer to the question posed above is: A. T-tubules. Transverse tubules (T-tubules) are structural components of the cell. They are essentially invaginations of the muscle cell membrane that are able to penetrate deep towards the middle of different types of muscle cells.