ANATOMY

Detailed explanation-1: -A myofibril (also known as a muscle fibril or sarcostyle) is a basic rod-like organelle of a muscle cell. Skeletal muscles are composed of long, tubular cells known as muscle fibers, and these cells contain many chains of myofibrils. Each myofibril has a diameter of 1–2 micrometres.

Detailed explanation-2: -Within the fasciculus, each individual muscle cell, called a muscle fiber, is surrounded by connective tissue called the endomysium. Skeletal muscle cells (fibers), like other body cells, are soft and fragile.

Detailed explanation-3: -Myofibrils are composed of overlapping thick and thin myofilaments organized into distinct, repeating units called sarcomeres. Z-discs (also called Z-lines; Z in Figures 5.1, 5.2), comprised largely of -actinin, form the boundaries of sarcomeres and provide an attachment site for thin filaments.

Detailed explanation-4: -19.4. 3 Skeletal muscle. Skeletal muscles are contractible organs with highly organized units (myofibers). The myofiber consists of a long, cylindrical, multinucleated cell resulted from fusion of multiple myotubes.

Detailed explanation-5: -The myofibrils have a characteristic banding pattern detected under a light microscope referred to as striations. The main function of the myofibrils is to produce muscle contraction and relaxation.