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

Introduction

The smooth muscle of the ampulla of Vater within the duodenal papillae.

Function

• regulation of bile and pancreatic flow into the duodenum
• diversion of hepatic bile into the gallbladder
• the prevention of reflux of duodenal contents into the pancreaticobiliary tract
• the resistance in the sphincter of Oddi decreases when the gall bladder contracts.
• cholecystokinin (CCK) & nitrates decrease the resistance offered by the sphincter

Structure

• the sphincter of Oddi consists of circular & longitudinal smooth muscle fibers surrounding a variable length of the distal bile and pancreatic duct
• there are three discrete areas of muscle thickness, or mini sphincters:
  • sphincter papillae
  • sphincter pancreaticus
  • sphincter choledochus

Pathology

• blockage of the sphincter of Oddi may result in pancreatitis in addition to biliary obstruction
• sphincter of Oddi dysfunction

More general terms

• sphincter

Additional terms

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