MUSCLE NERVE CARTILAGE BONE
SKELETAL MUSCLE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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the same length as the muscle fiber.
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the same length as a contracted sarcomere.
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longer than the length of a contracted sarcomere.
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shorter than the length of a contracted sarcomere.
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Detailed explanation-1: -The resting sarcomere is about 2.2 mm long.
Detailed explanation-2: -For a muscle cell to contract, the sarcomere must shorten. However, thick and thin filaments-the components of sarcomeres-do not shorten. Instead, they slide by one another, causing the sarcomere to shorten while the filaments remain the same length.
Detailed explanation-3: -If the resting length is shorter or longer, contraction is compromised. The effect of resting fiber length on muscular contraction is referred to as the length-tension relationship. This lesson will describe the anatomical arrangement of the muscle at rest and explain how this helps with muscular contraction.
Detailed explanation-4: -When (a) a sarcomere (b) contracts, the Z lines move closer together and the I band gets smaller. The A band stays the same width and, at full contraction, the thin filaments overlap. When a sarcomere shortens, some regions shorten whereas others stay the same length.