MICROANATOMY

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 filaments are composed of myosin with the globular heads forming cross-bridges with thin filaments.

Detailed explanation-3: -Most of the cytoplasm consists of myofibrils, which are cylindrical bundles of two types of filaments: thick filaments of myosin (about 15 nm in diameter) and thin filaments of actin (about 7 nm in diameter).

Detailed explanation-4: -Myosin filaments consist of myosin molecules, each having a tail of length 1500 Å and two elongated globular myosin heads, each with a dimension of 150 Å (Figure 3a). Myosin molecules comprise two heavy chains and four light chains.