MICROANATOMY

Detailed explanation-1: -According to sliding filament theory of muscle contraction, the actin and myosin filament slide past each other with the help of cross bridge to reduce the length of the sarcomeres. The smallest unit of muscle contraction is a sarcomere(which is delineated by Z-lines).

Detailed explanation-2: -The contractile functional unit of the myofibril is called the sarcomere, which is approximately 1.6–2.0 m in length. The different regions of the sarcomere are classified according to their ability to polarize light.

Detailed explanation-3: -The sarcomere is the fundamental contractile unit of the myofibril. Z lines separate each sarcomere. The A bands, located at the center of each sarcomere, contain the thick filaments, which may overlap with thin filaments.

Detailed explanation-4: -A sarcomere is the basic contractile unit of a myocyte (muscle fibre). A sarcomere is composed of two main protein filaments (thin actin and thick myosin filaments) which are the active structures responsible for muscular contraction.