smooth muscle

noun

: muscle tissue that lacks cross striations, is made up of elongated spindle-shaped cells having a central nucleus, and is found especially in vertebrate hollow organs and structures (such as the digestive tract and bladder) as thin sheets performing functions not subject to direct voluntary control and in all or most of the musculature of invertebrates other than arthropods compare striated muscle

Examples of smooth muscle in a Sentence

Recent Examples on the Web

In essence, these medications – known as PDE-5 inhibitors – work by preventing the breakdown of a signaling molecule, which in turn helps relax smooth muscle cells and dilate blood vessels. — Will Stone, NPR, 17 Aug. 2026

These include tenocytes [the primary component of tendons]; the cells that wrap around blood vessels and stabilize the circulatory system; the smooth muscle cells of the colon; and kidney epithelial cells, which filter toxins from the blood. — Ingrid Wickelgren, Quanta Magazine, 14 Aug. 2026

Snack Foods High in Calcium Calcium is a mineral that’s needed for the function of the smooth muscles in blood vessels that maintain your blood pressure and blood flow. — Jillian Kubala, Health, 11 May 2026

The glial cells have no smooth muscle cells. — Amanda Erickson, STAT, 7 Apr. 2026

Word History

First Known Use

circa 1890, in the meaning defined above

Rhymes for smooth muscle

• bustle
• hustle
• mussel
• russel
• rustle
• trussell
• tussle
• mofussil

Kids Definition

smooth muscle

noun

: muscle that is made up of long thin cells with a single nucleus and no cross stripes, that is found especially in hollow organs and parts (as the bladder and blood vessels), and that is not under voluntary control

called also involuntary muscle

compare striated muscle

Medical Definition

smooth muscle

noun

: muscle tissue that lacks cross striations, that is made up of elongated spindle-shaped cells having a central nucleus, and that is found especially in vertebrate hollow organs and structures (as the small intestine and bladder) as thin sheets performing functions not subject to direct voluntary control and in all or most of the musculature of invertebrates other than arthropods

called also nonstriated muscle, unstriated muscle

compare cardiac muscle, striated muscle