ANIMAL PHYSIOLOGY
MUSCLE ANIMAL
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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relaxes
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contracts
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freezes
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stretches
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Detailed explanation-1: -Muscles that work like this are called antagonistic pairs. In an antagonistic muscle pair as one muscle contracts the other muscle relaxes or lengthens. The muscle that is contracting is called the agonist and the muscle that is relaxing or lengthening is called the antagonist.
Detailed explanation-2: -Relaxation of a Skeletal Muscle The muscle fiber will repolarize, which closes the gates in the SR where Ca++ was being released. ATP-driven pumps will move Ca++ out of the sarcoplasm back into the SR. This results in the “reshielding” of the actin-binding sites on the thin filaments.
Detailed explanation-3: -Muscles can pull bones, but they can’t push them back to the original position. So they work in pairs of flexors and extensors. The flexor contracts to bend a limb at a joint. Then, when the movement is completed, the flexor relaxes and the extensor contracts to extend or straighten the limb at the same joint.