Body movements are mainly provided by mechanical function of skeletal muscle. Skeletal
muscle is composed of numerous bundles of myofibers that are sheathed by intramuscular
connective tissues. Each myofiber contains many myofibrils that run longitudinally along the
length of the myofiber. Myofibrils are the contractile apparatus of muscle and they are
composed of repeated contractile units known as sarcomeres. A sarcomere unit contains
actin and myosin filaments that are spaced by the Z discs and titin protein. Mechanical …