Pylorus

Definition

The pylorus is the distal opening of the stomach that connects to the small intestine. It acts as a valve, controlling the flow of food from the stomach into the duodenum, the first segment of the small intestine.

5 Must Know Facts For Your Next Test

1. The pylorus is responsible for controlling the rate at which food leaves the stomach and enters the small intestine.
2. The pyloric sphincter, a ring of smooth muscle, opens and closes to regulate the flow of food from the stomach to the duodenum.
3. The gastric antrum, the distal portion of the stomach, mixes and prepares the food for passage through the pylorus.
4. The pylorus helps maintain the optimal pH and consistency of the chyme (partially digested food) before it enters the small intestine.
5. Dysfunction of the pylorus, such as pyloric stenosis, can lead to obstructed gastric emptying and associated digestive issues.

Review Questions

• Describe the role of the pylorus in the digestive process.
  • The pylorus is the distal opening of the stomach that connects to the small intestine. It acts as a valve, controlling the flow of food from the stomach into the duodenum, the first segment of the small intestine. The pyloric sphincter, a ring of smooth muscle surrounding the pylorus, opens and closes to regulate the rate at which the partially digested food, or chyme, leaves the stomach and enters the small intestine. This controlled flow helps maintain the optimal pH and consistency of the chyme before it is further digested in the small intestine.
• Explain how the gastric antrum and pylorus work together to prepare food for intestinal digestion.
  • The gastric antrum, the distal portion of the stomach, plays a crucial role in preparing the food for passage through the pylorus. The antrum mixes and churns the food, breaking it down into a semi-liquid consistency known as chyme. The pylorus then controls the rate at which this chyme is released into the duodenum, the first segment of the small intestine. The pyloric sphincter, a ring of smooth muscle surrounding the pylorus, opens and closes to regulate the flow of chyme, ensuring that it has the appropriate pH and consistency for optimal digestion in the small intestine.
• Discuss the potential consequences of pyloric dysfunction and how it can impact the overall digestive process.
  • Dysfunction of the pylorus, such as pyloric stenosis, can lead to obstructed gastric emptying and associated digestive issues. When the pylorus is unable to properly regulate the flow of chyme from the stomach to the small intestine, it can result in delayed gastric emptying, nausea, vomiting, and other gastrointestinal symptoms. This disruption in the normal digestive process can also lead to complications, such as electrolyte imbalances, dehydration, and malnutrition, if the condition is left untreated. Understanding the critical role of the pylorus in maintaining the proper flow and consistency of digested food is essential for recognizing and managing pyloric dysfunction.

Related terms

Gastric Antrum: The distal portion of the stomach, located just before the pylorus, where food is mixed and prepared for passage into the small intestine.

Pyloric Sphincter:

A ring of smooth muscle that surrounds the pylorus, regulating the emptying of the stomach contents into the duodenum.

Duodenum:

The first and shortest segment of the small intestine, which receives the partially digested food from the stomach through the pylorus.