MEDICAL PHYSIOLOGY

Detailed explanation-1: -The thin and the thick filaments are arranged in a way that they overlap partially enabling them to slide past each other during contraction. The sarcomere is delimited by two Z discs (also called Z lines, Z bands, or intermediate discs).

Detailed explanation-2: -Z-discs (Z-disk, Z-line, Z-band) delineate the lateral borders of sarcomeres and are the smallest functional units in striated muscle. The core of a Z-disc consists of actin filaments coming from adjacent sarcomeres which are crosslinked by actinin molecules [1].

Detailed explanation-3: -Z-discs serve three main functions in the sarcomere: (1) stabilizing F-actin filament structures, (2) allowing force transfer between individual sarcomeres, and (3) acting as signaling centers communicating with the nucleus (Clark et al., 2002; Knoll et al., 2011; Sanger and Sanger, 2008).

Detailed explanation-4: -A sarcomere is defined as the region of a myofibril contained between two cytoskeletal structures called Z-discs (also called Z-lines or Z-bands), and the striated appearance of skeletal muscle fibers is due to the arrangement of the thick and thin myofilaments within each sarcomere (Figure 10.2. 2).