MUSCLE PHYSIOLOGY

Detailed explanation-1: -Smooth muscle uses actin and myosin filaments for contraction. The mechanism, illustrated in Figure 5-10, differs from that in skeletal muscle. Smooth muscle has tropomyosin but lacks troponin C. Calcium acts through calmodulin to activate myosin light-chain kinase to phosphorylate the myosin heads.

Detailed explanation-2: -The striations of skeletal muscle are created by the organization of actin and myosin filaments resulting in the banding pattern of myofibrils. These actin and myosin filaments slide over each other to cause shortening of sarcomeres and the cells to produce force.