MICROANATOMY

Detailed explanation-1: -Those that are not under the control of the will (volition) are called involuntary muscles. Smooth muscles are involuntary muscles.

Detailed explanation-2: -Smooth muscle, found in the walls of the hollow internal organs such as blood vessels, the gastrointestinal tract, bladder, and uterus, is under control of the autonomic nervous system. Smooth muscle cannot be controlled consciously and thus acts involuntarily.

Detailed explanation-3: -Smooth muscle fibers are located in walls of hollow visceral organs (such as the liver, pancreas, and intestines), except the heart, appear spindle-shaped, and are also under involuntary control.

Detailed explanation-4: -So there is actually no smooth muscle that is voluntary. Voluntary muscle tissue would be muscles that are controlled consciously such as skeletal muscle which is used for movement. Smooth muscle is used in organs such as the uterus which unconsciously contract during events such as child birth.

Detailed explanation-5: -Types of Smooth muscle Smooth muscles are of two types. They are: Single-unit (visceral) smooth muscle: All the cells function collectively and simultaneously as a single unit (unitary). Multiunit smooth muscle: It is a type of muscle in which all the cells cannot function collectively and work independently.