Magenausgang

Magenausgang is the distal portion of the stomach that leads into the duodenum. In anatomy it corresponds to the pylorus, which comprises the pyloric antrum, the pyloric canal, and the pyloric sphincter, a circular muscle that guards the pyloric outlet.

The pyloric region marks the transition from stomach to small intestine. The antrum lies proximal to the canal, and the canal ends at the pyloric sphincter, which forms the actual gateway to the duodenum. The sphincter regulates the rate at which gastric contents are emptied and prevents backflow of chyme from the duodenum into the stomach.

Physiology and regulation: Peristaltic contractions in the antrum drive chyme toward the pylorus, where the sphincter intermittently opens to release small amounts into the duodenum. Gastrin, neural input via the vagus nerve, and other hormonal factors promote coordinated emptying, while hormones such as cholecystokinin and secretin slow gastric emptying. The composition of a meal influences the rate: fats and proteins typically slow progression more than carbohydrates.

Clinical relevance: Conditions affecting the Magenausgang include pyloric stenosis, most notably congenital hypertrophic pyloric stenosis in infants, which causes nonbilious projectile vomiting and is treated with pyloromyotomy. Other issues such as gastric outlet obstruction or peptic ulcers near the pylorus can impair emptying and require medical or surgical management.

Terminology: The term Magenausgang is German for the stomach outlet and is commonly described in English as the pylorus or pyloric region, with the sphincter acting as the functional gateway.