PHYSIOLOGY
MUSCLE STRUCTURE FUNCTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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sarcolemma
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myofibrils
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sarcoplasm
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sarcomeres
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Detailed explanation-1: -The sarcomere is the fundamental unit of contraction and is defined as the region between two Z-lines. Each sarcomere consists of a central A-band (thick filaments) and two halves of the I-band (thin filaments ). The I-band from two adjacent sarcomeres meets at the Z-line.
Detailed explanation-2: -– Z-lines define the boundaries of each sarcomere. – The M-line runs down the center of the sarcomere, through the middle of the myosin filaments. – The I-band is the region containing only thin filaments. – The H-zone contains only thick filaments.
Detailed explanation-3: -The Z-line defines the lateral boundary of each sarcomere. Contraction of the sarcomere occurs when the Z-lines move closer together, making the myofibrils contract, and therefore the whole muscle cell and then the entire muscle contracts.