Pyloric sphincter

Pyloric Sphincter

The Pyloric Sphincter is a muscle that forms part of the gastrointestinal tract. It is a circular muscle located at the junction between the pylorus of the stomach and the duodenum of the small intestine. Its primary function is to regulate the passage of partially digested food, known as chyme, from the stomach to the small intestine.

Structure

The Pyloric Sphincter is a thickened muscular ring, approximately 1-2 cm in diameter. It is located at the distal end of the stomach and proximal end of the duodenum. The muscle fibers of the sphincter are oriented in a circular manner, allowing it to contract and relax in a coordinated fashion.

Function

The primary function of the Pyloric Sphincter is to regulate the passage of chyme from the stomach to the small intestine. It does this by contracting and relaxing in response to various signals. When the stomach is full, the sphincter contracts, preventing the passage of chyme. As the stomach empties, the sphincter relaxes, allowing chyme to pass into the small intestine.

Clinical significance

Dysfunction of the Pyloric Sphincter can lead to a number of medical conditions. For example, Pyloric stenosis is a condition in which the sphincter becomes abnormally narrow, preventing the passage of chyme and leading to vomiting and weight loss. This condition is most commonly seen in infants and is typically treated with surgery.

Gastroesophageal reflux disease (GERD) can also be caused by dysfunction of the Pyloric Sphincter. In this condition, the sphincter fails to close properly, allowing stomach acid to flow back into the esophagus and causing heartburn and other symptoms.

See also

• Gastrointestinal tract
• Stomach
• Duodenum
• Pylorus
• Muscle

References

Pyloric sphincter Resources
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