pyloric sphincter

anatomy

Also known as: sphincter pylori

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 13, 2026

Quick Summary

The pyloric sphincter is a ring of muscle located at the end of the stomach, where it meets the small intestine. Its primary role is to control the passage of food from the stomach into the duodenum, the first part of the small intestine.

This sphincter remains mostly open, allowing small amounts of partially digested food to move into the intestine. When the duodenum fills, the sphincter tightens, preventing food from re-entering the stomach and ensuring that food moves further into the digestive tract. The pyloric sphincter also prevents large food particles from entering the intestine. While crucial for digestion, surgical removal of this sphincter does not significantly impact the stomach's emptying process.12

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

pylorus
…circular muscle tissue allows the pyloric sphincter to open or close, permitting food to pass or be retained. The sphincter remains in an open or relaxed state two-thirds of the time, permitting small quantities of food to pass into the duodenum, the upper portion of the small intestine. When the…
Read More
…circular muscle tissue allows the pyloric sphincter to open or close, permitting food to pass or be retained. The sphincter remains in an open or relaxed state two-thirds of the time, permitting small quantities of food to pass into the duodenum, the upper portion of the small intestine. When the…
Read More