Question

Draw a diagram of smooth muscle fiber and label any three parts.

Answer 1

Smooth muscle -

1. The cells of smooth muscles are long with pointed ends having a spindle shape.
2. They are unbranched and uninucleate i.e. have a single nucleus.
3. They are also called Unstriated muscles because of the absence of bands or stripes or striations.
4. The cells of the smooth muscles are held together by loose connective tissue. There are delicate contractile threads called myofibrils running longitudinally throughout the cell.

Location: The smooth muscles are found in the walls of the visceral organs and hence are called visceral muscles. The smooth muscles are also found in the iris of the eye, in ureters, blood vessels, intestine, and in the bronchi of the lungs.

Diagram of smooth muscle fibers -