Animal Tissue — Biology STD 11 Science — Question

Smooth muscles are also known as non-striated, visceral or involuntary muscles.
Structure:

1. These muscles are present in the form of sheets or layers.
2. Each muscle cell is spindle shaped or fusiform.
3. The fibres are unbranched and have a single nucleus that is located centrally.
4. The sarcoplasm contains myofibrils which are made up of the contractile proteins – actin and myosin.
5. Smooth muscles contain less myosin and more actin.
6. Striations are absent, hence smooth muscles are also known as non-striated muscles,
7. These muscles are innervated by the autonomous nervous system.

Location:
It is found in walls of visceral organs and blood vessels. Therefore, smooth muscles are also known as visceral muscles.
Function:
Smooth muscles are associated with involuntary movements of the body like peristaltic movement of food through the digestive system.