MUSCLE PHYSIOLOGY

Detailed explanation-1: -In striated muscle cells, myosin forms the backbone of the thick filaments, which are anchored within the M-band and extend bidirectionally toward the two opposite ends of the sarcomere (171, 247).

Detailed explanation-2: -The thick filament, myosin, has a double-headed structure, with the heads positioned at opposite ends of the molecule. During muscle contraction, the heads of the myosin filaments attach to oppositely oriented thin filaments, actin, and pull them past one another.

Detailed explanation-3: -An individual sarcomere contains many parallel actin (thin) and myosin (thick) filaments.

Detailed explanation-4: -An important feature of myosin polymerization is that myosin-II molecules are oriented in opposite directions in each half of the sarcomere. This orientation results in polarized thick filaments that help in directing force toward the center of the sarcomere.

Detailed explanation-5: -Myosin forms thick filaments (15 nm in diameter) and actin forms thinner filaments (7nm in diameter). Actin and myosin filaments work together to generate force. This force produces the muscle cell contractions that facilitate the movement of the muscles and, therefore, of body structures.