bn:00056409n
Noun Concept
Categories: Perineum, Wikipedia articles incorporating text from the 20th edition of Gray's Anatomy (1918), Anus
EN
musculus sphincter ani internus  internal anal sphincter  sphincter ani internus muscle  Anal internal sphincter  Internal anal sphincter muscle
EN
An internal ring of smooth muscle formed by circular fibers of the rectum WordNet 3.0
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EN
An internal ring of smooth muscle formed by circular fibers of the rectum WordNet 3.0 & Open English WordNet
The internal anal sphincter, IAS, is a ring of smooth muscle that surrounds about 2.5–4.0 cm of the anal canal. Wikipedia
Detailed B&W medical cross-section diagram of both internal anal sphincter/rectum tissues. Wikidata