MICROANATOMY

Detailed explanation-1: -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. Thick filaments are anchored in the middle of the sarcomere at the M-line.

Detailed explanation-2: -Z-discs can be defined as plate-like structures in sarcomeres to which the plus ends of actin filaments are localized, or they can be defined as the centre of the I-band.

Detailed explanation-3: -At the boundaries of the sarcomeres, a multiprotein complex termed the Z-disk tethers actin-rich thin filaments. The Z-disk plays an integral role in the structure and function of striated muscle; it provides, together with the M-band tethering thick filaments, the structural integrity of the sarcomeres.