GENERAL HISTOLOGY

Detailed explanation-1: -The thick filaments of muscle consist of several hundred myosin molecules, associated in a parallel staggered array by interactions between their tails (Figure 11.23). The globular heads of myosin bind actin, forming cross-bridges between the thick and thin filaments.

Detailed explanation-2: -The thick filaments are composed of myosin, and the thin filaments are predominantly actin, along with two other muscle proteins, tropomyosin and troponin. Muscular contraction is caused by the interaction between actin and myosin as they temporarily bind to each other and are released.

Detailed explanation-3: -Myofibrils Are Composed of Actin and Myosin Filaments Each myofibril (Figure 6-1D andE) is composed of about 1500 adjacentmyosin filaments and 3000actin filaments, which are large polymerized protein molecules that are responsible for the muscle contraction.