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What happens when calcium ions are present in the cytosol of the muscle cell?

A. The motor end plate depolarizes.
B. Acetylcholine is released from synaptic vesicles.
C. The sarcomeres relax.
D. The muscle contracts.

User Alaamh
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1 Answer

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Final answer:

When calcium ions are present in the cytosol of the muscle cell, it triggers a series of events that lead to muscle contraction.

Step-by-step explanation:

When calcium ions are present in the cytosol of the muscle cell, several events occur that lead to muscle contraction. First, acetylcholine (ACh) is released from synaptic vesicles and binds to receptors on the sarcolemma. This triggers an action potential that travels along the T-tubules and causes the release of calcium ions from the sarcoplasmic reticulum (SR). The calcium ions then bind to actin, allowing for the formation of cross-bridges with myosin and initiating muscle contraction.

User Abraham Qian
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