The pyloric sphincter is a kind of muscular constriction, located at the end of the stomach, responsible for regulating the passage of semi-digested food from the stomach to the duodenum. This is the muscle that controls the exit of the stomach chyme.
Depending on the opening of the pyloric sphincter between the small intestine and the stomach, speed control for gastric emptying may be greater or lesser.
Food contrition is as important as sphincter relaxation so that food can pass. Preventing reflux from occurring.