Muscle, Smooth

**Definition:** Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)

**Tree numbers:** - A02.633.570 - A10.690.467

**Synonyms:** - Muscle, Involuntary - Smooth Muscle