ANATOMY

Detailed explanation-1: -myofibril, muscle fiber, filament, fascicle .

Detailed explanation-2: -Hence, the organization of muscle tissue from the largest to the smallest is a muscle, fascicle, myofibril, and myofilaments.

Detailed explanation-3: -Microscopic level-sarcomere and myofibrils. Cell level-myoblasts and myofibers. Tissue level-neuromuscular junctions and fascicles. Organ level-major skeletal muscles of the body.

Detailed explanation-4: -Myofibrils are composed of smaller structures called myofilaments.

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.