GENERAL HISTOLOGY

Detailed explanation-1: -Contractility refers to the capacity of muscle to contract or shorten forcefully. Muscles can be stretched to their normal resting length and beyond to a limited degree. This is because of extensibility. If muscles are stretched, they recoil to their original resting length because of its elasticity.

Detailed explanation-2: -Myofibrils run the entire length of the muscle fiber, and because they are only approximately 1.2 µm in diameter, hundreds to thousands can be found inside one muscle fiber. They attach to the sarcolemma at their ends, so that as myofibrils shorten, the entire muscle cell contracts (Figure 19.34).