ANATOMY

Detailed explanation-1: -muscle fiber. myofilament. myofibril. muscle fasciculus.

Detailed explanation-2: -Based on the dimensions, the above-mentioned structures can be arranged in the following way from the largest to the smallest component: Muscle fiber → Myofibril → Sarcomere → Thin-filaments →Troponin.

Detailed explanation-3: -Of all the answers, the largest structure is the fascicle. Fascicles are made up of muscle fibers and muscle fibers are made up of myofibrils.

Detailed explanation-4: -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-5: -The smallest contractile unit of skeletal muscle is the muscle fiber or myofiber, which is a long cylindrical cell that contains many nuclei, mitochondria, and sarcomeres (Figure 1) [58]. Each muscle fiber is surrounded by a thin layer of connective tissue called the endomysium.