The sphincter muscle which connects the bottom of the stomach (or pylorus) to the duodenum. Also called the pyloric sphincter. This valve can open and close, allowing gastric contents to progress further into the digestive system.

One interesting event which can cause the pyloric valve to close is alcohol intoxication. Once the body has absorbed a certain amount of alcohol, the valve closes to stop further absorption. As the alcoholic continues to drink, more and more alcohol piles up in the stomach, killing the epithelium and causing vomiting.