MEDICAL PHYSIOLOGY

Detailed explanation-1: -Skeletal and cardiac muscle are referred to as striated muscle because of the visible organization of repeating units of contractile filaments, known as sarcomeres, into cylindrical bundles called myofibrils.

Detailed explanation-2: -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.

Detailed explanation-3: -Sarcomerum. Synonyms: Myomere, Myomerum. The sarcomere is the main contractile unit of muscle fiber in the skeletal muscle. Each sarcomere is composed of protein filaments (myofilaments) that include mainly the thick filaments called myosin, and thin filaments called actin.

Detailed explanation-4: -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).