sphincter of Oddi; sphincter of the hepatopancreatic/bilaropancreatic ampulla; Glisson sphincter

The smooth muscle of the ampulla of Vater within the duodenal papillae. Function: 1) regulation of bile and pancreatic flow into the duodenum 2) diversion of hepatic bile into the gallbladder 3) the prevention of reflux of duodenal contents into the pancreaticobiliary tract 4) the resistance in the sphincter of Oddi decreases when the gall bladder contracts. 5) cholecystokinin (CCK) & nitrates decrease the resistance offered by the sphincter Structure: 1) the sphincter of Oddi consists of circular & longitudinal smooth muscle fibers surrounding a variable length of the distal bile and pancreatic duct 2) there are three discrete areas of muscle thickness, or mini sphincters: a) sphincter papillae b) sphincter pancreaticus c) sphincter choledochus Pathology: - blockage of the sphincter of Oddi may result in pancreatitis in addition to biliary obstruction - sphincter of Oddi dysfunction

Related

ampulla of Vater (hepatopancreatic, bilaropancreatic ampulla) sphincter of Oddi dysfunction

References

Stedman's Medical Dictionary 27th ed, Williams & Wilkins, Baltimore, 1999.