PHYSIOLOGY
MUSCLE CONTRACTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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an impulse reaches the neuromuscular junction
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an impulse is transmitted along the T tubule
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ATP binds to sarcoplasmic reticulum
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acetylcholine binds to ligand gated ion channels
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Detailed explanation-1: -When the muscle is stimulated, calcium ions are released from its store inside the sarcoplasmic reticulum, into the sarcoplasm (muscle ). Invaginations of the plasma membrane (sarcolemma) of the muscle fibres are called T (or transverse) tubules.
Detailed explanation-2: -Answer and Explanation: Calcium is released from the sarcoplasmic reticulum as an action potential passes through the T tubules.
Detailed explanation-3: -A muscle action potential propagating along a transverse tubule opens Ca2+ release channels in the sarcoplasmic reticulum (SR), calcium ions flow into cytosol, and contraction begins. 3. Ca2+ binds to troponin, which changes the shape of the troponin-tropomyosin complex and uncovers the myosin-binding sites on actin.