What regulates bile flow into the duodenum at the Ampulla of Vater?

The Sphincter of Oddi is a muscular valve that plays a crucial role in regulating the flow of bile and pancreatic enzymes into the duodenum at the Ampulla of Vater. This sphincter controls the timing and amount of bile released from the gallbladder and pancreatic juices from the pancreas into the small intestine, allowing for proper digestion of fats and the neutralization of stomach acid.

When food enters the duodenum, hormones such as cholecystokinin stimulate the Sphincter of Oddi to relax, enabling bile to flow into the digestive tract. This action is essential for the emulsification of fats and the facilitation of nutrient absorption.

Other options, such as the pyloric sphincter, primarily regulate the flow of chyme from the stomach to the duodenum, while the cardiac sphincter, also known as the lower esophageal sphincter, prevents the backflow of stomach contents into the esophagus. The enteric nerve plexus is involved in coordinating bowel movements and digestive activity but does not directly regulate the flow of bile at the Sphincter of Oddi. Therefore, the Sphincter of Oddi is specifically responsible for controlling bile flow into the duodenum