PHYSIOLOGY
MUSCLE CONTRACTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Passive process
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Active process
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Either A or B
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None of the above
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Detailed explanation-1: -Is relaxation an active process? Measurements of muscle heat production had indicated that relaxation is not an active process.
Detailed explanation-2: -Neuroimaging and neurophysiological studies suggest that muscle relaxation is an active process requiring cortical activation, and not just the cessation of contraction.
Detailed explanation-3: -Relaxation: Relaxation occurs when stimulation of the nerve stops. Calcium is then pumped back into the sarcoplasmic reticulum breaking the link between actin and myosin. Actin and myosin return to their unbound state causing the muscle to relax.
Detailed explanation-4: -If active relaxation occurred the latent period would be greatly increased. A resting muscle exerts measurable tension down to 60 to 75% of its natural length in the body. By previous stimulation at a shorter length the range of lengths within which measurable tension is exerted is increased.