Sphincter of Oddi

Overview
The Sphincter of Oddi, also called the hepatopancreatic sphincter or Glisson's sphincter, controls secretions from the liver, pancreas, and gallbladder into the duodenum of the small intestine.

It is a sphincter muscle located at the surface of the duodenum. It appears slightly distal to the joining of the common bile duct and pancreatic duct as they enter the descending duodenum and forms from the ampulla of Vater. Bile and pancreatic secretions enter the digestive system through this point. The opening on the inside of the descending duodenum after the sphincter of Oddi is called the major duodenal papilla.

Clinical significance
Endoscopic retrograde cholangiopancreatograms (ERCPs), which are radiographic examinations of the biliary system, often involve assessment of the bile ducts with a esophagogastroduodenoscopy via the sphincter of Oddi before the injection of iodinated contrast medium.