ANATOMY

Detailed explanation-1: -Sarcomeres. A sarcomere is the functional unit (contractile unit) of a muscle fiber. As illustrated in Figure 2-5, each sarcomere contains two types of myofilaments: thick filaments, composed primarily of the contractile protein myosin, and thin filaments, composed primarily of the contractile protein actin.

Detailed explanation-2: -Sarcomere is the structural & functional unit of muscle.

Detailed explanation-3: -The sarcomere is the smallest functional unit of a skeletal muscle fiber and is a highly organized arrangement of contractile, regulatory, and structural proteins. It is the shortening of these individual sarcomeres that lead to the contraction of individual skeletal muscle fibers (and ultimately the whole muscle).

Detailed explanation-4: -Answer and Explanation: The functional unit of a muscle myofibril is called a sarcomere. The sarcomere is composed of overlapping actin and myosin filaments that form a cross bridge with each other and slide past each other resulting in the shortening of the sarcomere.