sphincter of Oddi
Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
a circular muscle that constricts a passage or closes a natural orifice. When relaxed, a sphincter allows materials to pass through the opening. When contracted, it closes the opening. Four main sphincter muscles along the alimentary canal aid in digestion: the cardiac sphincter, the pyloric sphincter, and two anal sphincters. Other sphincters are found in the iris of the eye, the bile duct (sphincter of Oddi), the urinary tract, and elsewhere.
anal sphincter (sphincter a´ni) either of two sphincters (the internal and external anal sphincters) that open and close to control evacuation of feces from the anus.
cardiac sphincter a sphincter between the esophagus and the stomach, opening at the approach of food that can then be swept into the stomach by rhythmic peristaltic waves.
sphincter of Oddi a sheath of muscle fibers investing the associated bile and pancreatic passages as they traverse the wall of the duodenum.
pyloric sphincter a sphincter at the opening from the stomach into the duodenum; it is usually closed, opening only for a moment when a peristaltic wave passes over it.
urinary sphincter, artificial a fluid-filled system that surrounds the urethra with a silicone cuff that functions as a sphincter; a pump is in the scrotum and a fluid reservoir is in the abdomen. For urination, the pump's release valve is squeezed to allow the fluid to leave the urethral cuff and return to the reservoir; after urination is complete, the pump is squeezed and the fluid returns to the cuff to occlude the urethra.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
sphinc·ter of Od·di(sfingk'tĕr od'ē)
A valvelike muscular sheath surrounding the distal pancreatic and common bile ducts as they enter the duodenum together.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
sphincter of OddiThe smooth muscle ring that surrounds the common bile duct at the point at which it enters the DUODENUM. (Ruggero Oddi, Italian physician, 1864–1913).
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
Oddi,Ruggero, Italian physician, 1864-1913.
sphincter of Oddi - the smooth muscle sphincter of the hepatopancreatic ampulla within the duodenal papilla. Synonym(s): sphincter of hepatopancreatic ampulla
Medical Eponyms © Farlex 2012