ANATOMY

Detailed explanation-1: -A-band contains both actin and myosin. M-line and Z-line are in the middle of thick and thin filaments, respectively.

Detailed explanation-2: -The myofibrils contain thick and thin filaments. The arrangement of thick myosin filaments along the myofibrils and the cell cause them to refract light and produce a dark band which is known as an A band. The anisotropic band is composed of both thick and thin filaments.

Detailed explanation-3: -Myosin filaments, the thick filaments, are bipolar and extend throughout the A-band.

Detailed explanation-4: -The thin filaments contain actin, tropomyosin, troponins C, I, and T and nebulin. The thick filaments are composed of myosin with the globular heads forming cross-bridges with thin filaments. Myosin-binding proteins, including MyBP-C, are associated with the thick filaments.