ANATOMY

Detailed explanation-1: -The I bands contain only thin (actin) filaments, whereas the A bands contain thick (myosin) filaments. The myosin and actin filaments overlap in peripheral regions of the A band, whereas a middle region (called the H zone) contains only myosin.

Detailed explanation-2: -Actin and myosin are found in almost all eukaryotic cells and are required for diverse cellular functions, including muscle contraction, cell motility, cell adhesion, cytokinesis, and organelle transport (1).

Detailed explanation-3: -There are two types of myofilaments. Thin actin filament and thick myosin filament. Both the filaments are arranged alternately. The region where both myofilaments are present is seen as dark and is called as dark band.

Detailed explanation-4: -They are myosin (thick filament) and myosin (thin filament) (actin). Throughout the length of the myofibrils, the ‘A’ and ‘I’ bands are alternately organized. The anisotropic band in skeletal muscle is also known as the A band. Actin filaments and myosin filaments make up the anisotropic band.