The pylorus is the lower, muscular portion of the stomach that connects to the duodenum (the first part of the small intestine). It acts as a valve, controlling the passage of partially digested food and stomach contents from the stomach into the small intestine. This controlled release is crucial for efficient digestion.
Understanding the Pylorus: Structure and Function
The pylorus is not a single, homogenous structure; rather, it consists of two main parts:
- Pyloric Antrum: This is the wider, upper part of the pylorus, leading from the main body of the stomach.
- Pyloric Canal: This is the narrower, lower part of the pylorus, connecting directly to the duodenum.
The pylorus contains a thick ring of muscle called the pyloric sphincter. This sphincter opens and closes rhythmically, regulating the flow of chyme (partially digested food) into the duodenum. This controlled release prevents the small intestine from being overwhelmed and ensures optimal nutrient absorption.
Clinical Significance: Pyloric Stenosis
One notable clinical condition related to the pylorus is pyloric stenosis. This condition, most commonly affecting infants, involves a narrowing of the pyloric sphincter, obstructing the passage of food from the stomach to the small intestine. Symptoms include forceful vomiting, dehydration, and weight loss. Surgical intervention (pyloromyotomy) is typically required to correct the blockage. (Mayo Clinic, Johns Hopkins Medicine, Nationwide Children's Hospital)
The Pylorus in the Context of Digestion
The pylorus plays a vital role in the digestive process. Its controlled opening and closing ensures that:
- The small intestine receives chyme at a manageable rate.
- The stomach can thoroughly mix and churn food before release.
- Digestion proceeds efficiently throughout the digestive tract.
(Reference: Definition from provided text)
