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This video will discuss the mechanism of muscle contraction.
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As we know that muscles, these are responsible in the movement of body parts.
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This occurs due to the contraction of muscles.
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There are four steps involved in the contraction of muscles and these four steps are.
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The first step of the muscle contraction involves depolarization, and calcium release into the cytoplasm of the muscle cells.
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In the second step, the actin and myosin they form a cross bridge.
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The third step is sliding of actin and myosin over each other, and the fourth one is the shortening of the sarcomere.
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Now let's discuss them one by one.
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Depolarization occurs due to the motor signals, which are coming from the central nervous system, these motor signals, these excite the muscle cells and release calcium ions from the sarcoplasmic reticulum.
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It is the endoplasmic reticulum of the muscle cells that stores the calcium ions.
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These calcium ions, they bind to the protein called the troponin.
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Hence, it exposes the binding site for the myosin.
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Or we can say, myosin binding site.
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This exposing of binding, myosin binding site will lead to the second step of the muscle contraction, which is actin and myosin cross -bridge form...