Write about structure and function of smooth muscle fibres.

Smooth muscles also called as unstriated muscles as they lack transverse striations. They are not under the control of one’s will, hence they are also called involuntary muscles. These muscle cells are long with pointed ends (spindle shaped) and arranged in bundles. Each cell is uninucleated (having a single nucleus).

Smooth muscles are found in alimentary canal and blood vessels. The movement of food in the alimentary canal or the contraction and relaxation of blood vessels are involuntary movement. These are also found in the iris of the eye, in uterus and in the bronchi of the lungs.