MUSCLE PHYSIOLOGY

Detailed explanation-1: -The correct answer: During muscle contraction, myosin cross-bridges attach to B) actin filaments. Muscle contraction is a process in which the interaction between the muscle filaments takes place. The actin and myosin filaments interact with the help of the sliding movement of actin which occurs on myosin.

Detailed explanation-2: -Cross-bridges can only form where thick and thin filaments overlap, allowing myosin to bind to actin. If more cross-bridges are formed, more myosin will pull on actin, and more tension will be produced.

Detailed explanation-3: -If the actin binding sites are uncovered, a cross-bridge will form; that is, the myosin head spans the distance between the actin and myosin molecules. Pi is then released, allowing myosin to expend the stored energy as a conformational change. The myosin head moves toward the M line, pulling the actin along with it.