MUSCLE PHYSIOLOGY

Detailed explanation-1: -Myofibrils are made up of sarcomeres, the functional units of a muscle. The function of the myofibril is to perform muscle contraction via the sliding-filament model . When muscles are at rest, there is incomplete overlap between the thin and thick filaments, with some areas containing only one of the two types.

Detailed explanation-2: -Myofibrils constitute the contractile system, which consists of four complex proteins: myosin, actin, tropomyosin, and troponin. These four proteins are arranged into a functional unit called a sarcomere (see Fig.

Detailed explanation-3: -Skeletal and cardiac muscles are known as striated muscles, because the filaments of actin and myosin that power their contraction are organized into repeating arrays, called sarcomeres, that have a striated microscopic appearance.