Smooth muscle facts for kids

Quick facts for kids Smooth muscle tissues
Layers of Esophageal Wall: Mucosa Submucosa Muscularis Adventitia Striated muscle Striated and smooth Smooth muscle Lamina muscularis mucosae Esophageal glands
Latin	textus muscularis levis; textus muscularis nonstriatus

Smooth muscle tissue, highlighting the circular layer (nucleuses then rest of cells), longitudinal layer (nucleuses then rest of cells), then the serous membrane facing the lumen of the peritoneal cavity

Smooth muscle is an involuntary non-striated muscle. It is divided into two subgroups; the single-unit (unitary) and multiunit smooth muscle. Within single-unit cells, the whole bundle or sheet contracts as a syncytium.

Smooth muscle cells are found in the walls of hollow organs, including the stomach, intestines, urinary bladder and uterus, and in the walls of passageways, such as the arteries and veins of the circulatory system, and the tracts of the respiratory, urinary, and reproductive systems. These cells are also present in the eyes and are able to change the size of the iris and alter the shape of the lens. In the skin, smooth muscle cells cause hair to stand erect in response to cold temperature or fear.

Images for kids

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  A series of axon-like swellings, called varicosities from autonomic neurons, loosely form motor units through the smooth muscle.

See also

In Spanish: Músculo liso para niños