sphincter of Oddi

sphincter /sphinc·ter/ (sfingk´ter) [L.] a ringlike muscle which closes a natural orifice or passage.sphinc´teralsphincter´ic

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anal sphincter , sphincter a´ni sphincter muscle of anus (external or internal).

cardiac sphincter , cardioesophageal sphincter muscle fibers about the opening of the esophagus into the stomach.

external sphincter of female urethra  external sphincter muscle of female urethra.

external sphincter of male urethra  external sphincter muscle of male urethra.

gastroesophageal sphincter  the terminal few centimeters of the esophagus, which prevents reflux of gastric contents into the esophagus.

hepatic sphincter  a thickened portion of the muscular coat of the hepatic veins near their entrance into the inferior vena cava.

internal sphincter of urethra  internal sphincter muscle of urethra.

O'Beirne's sphincter  a band of muscle at the junction of the sigmoid colon and rectum.

sphincter of Oddi  the sheath of muscle fibers investing the associated bile and pancreatic passages as they traverse the wall of the duodenum.

pharyngoesophageal sphincter  a region of higher muscular tone at the junction of the pharynx and esophagus, which is involved in movements of swallowing.

precapillary sphincter  a smooth muscle fiber encircling a true capillary where it originates from the arterial capillary, which can open and close the capillary entrance.

pyloric sphincter  see under muscle.

rectal sphincter  an incomplete band or thickening of the muscle fibers in the rectum a few inches above the anus in the upper part of the rectal ampulla.

tubal sphincter  an encircling band of muscle fibers at the junction of the uterine tube and the uterus.

vesical sphincter  internal sphincter muscle of urethra.

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sphincter of Oddi

Etymology: Ruggero Oddi, Italian physician, 1864-1913

a sheath of muscle fibers surrounding the lower end of the common bile and pancreatic ducts as they cross the wall of the duodenum.

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sphincter [sfingk´ter]

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.

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sphincter

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. The principal abnormalities relate to function. Failure to open may be because of spasm or achalasia, due usually to failure of parasympathetic nerve supply. Failure to close usually due to absence of sympathetic nerve supply. The important sphincters are the anal, ileal, pharyngoesophageal, pupillary, pyloric, reticulo-omasal, teat, urethral, vaginal and vesical.

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cardiac sphincter

the functional sphincter at the gastric end of the esophagus.

sphincter control

is by the autonomic nervous system.

esophageal sphincter

see cardiac sphincter.

sphincter of Oddi

bile duct sphincter.

pupillary sphincter

a ring of smooth muscle around the pupillary border of the iris.