Sphincter

A sphincter is an anatomical structure, a circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning. Sphincters are found in many animals; there are over 50 types in the human body, some microscopically small, in particular the millions of precapillary sphincters.

Read more about Sphincter:  Functions, Classifications, Examples

Other articles related to "sphincter, sphincters":

Lateral Internal Sphincterotomy - Surgical Technique
... the intersphincteric groove, separating the internal sphincter from the anal mucosa by blunt dissection, and dividing the internal sphincter using scissors ... with the blade parallel to the internal sphincter and advancing it along the intersphincteric groove, and then rotating the scalpel towards the internal sphincter and ...
Sphincter Paralysis
... Sphincter paralysis is paralysis of one of the body's many sphincters, preventing it from constricting normally ... may remain continent for many years despite being affected by anal sphincter paralysis ...
Sphincter - Examples
... The sphincter pupillae, or pupillary sphincter, belonging to the iris in the eye ... The upper oesophageal sphincter ... The cardia (lower esophageal sphincter), or cardiac sphincter, at the upper portion of the stomach ...
Human Anus - Health
... The risk of injury to the anal sphincter should be a concern ... Sphincter exercise can improve the tone of the outer sphincter muscle ...
Sphincter Of Ampulla
... The sphincter of ampulla or sphincter of Oddi is a muscular valve that controls the flow of digestive juices (bile and pancreatic juice) through the ampulla of Vater into ... The sphincter of Oddi is relaxed by the hormone cholecystokinin (CCK) via vasoactive intestinal polypeptide (VIP) ...