musculus sphincter ani internus
Also found in: Thesaurus, Medical, Wikipedia.
Switch to new thesaurus
|Noun||1.||musculus sphincter ani internus - an internal ring of smooth muscle formed by circular fibers of the rectum|
involuntary muscle, smooth muscle - a muscle that contracts without conscious control and found in walls of internal organs such as stomach and intestine and bladder and blood vessels (excluding the heart)
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.