MEDICAL PHYSIOLOGY

Detailed explanation-1: -They could see length of the sarcomere when relaxed and its shortening as it contracted, and were able to give names to particular zones. A bands (or anisotropic bands): It is also called the dark band and contains the whole thick filament (myosin).

Detailed explanation-2: -Inside a sarcomere there are several regions. One such region is the I band, which consists of the actin filaments in the region where they are not superimposed by the myosin filaments. This means that the I band consists only of actin filaments; however, actin filaments aren’t exclusive to the I band.

Detailed explanation-3: -The Z-band (or Z-disk) is a dense fibrous structure made of actin, -actinin, and other proteins. Thin filaments (or actin filament) are anchored at one end at the Z-band. Titin is anchored to both the Z-band and the M-line.

Detailed explanation-4: -The sarcomere consists of a bundle of myosin-containing thick filaments flanked and interdigitated with bundles of actin-containing thin filaments (Fig. 1). The striated appearance of muscle results from the alternation of thick-filament-containing (A-Band) and thin-filament-containing (I-band) regions.