PHYSIOLOGY
MUSCLE CONTRACTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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I band
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A band
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H-zone
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Z disc
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Detailed explanation-1: -Thin filaments (or actin filament) are anchored at one end at the Z-band. Titin is anchored to both the Z-band and the M-line. Thick filaments are anchored in the middle of the sarcomere at the M-line. The I-band is the region on either side of a Z-disc that contains only thin filaments and titin.
Detailed explanation-2: -Because actin is tethered to structures located at the lateral ends of each sarcomere called z discs or “z bands, ‘’ any shortening of the actin filament length would result in a shortening of the sarcomere and thus the muscle.
Detailed explanation-3: -The actin filaments are attached at their plus ends to the Z disc, which includes the crosslinking protein -actinin. The myosin filaments are anchored at the M line in the middle of the sarcomere.