pyloric

Pyloric refers to the pylorus, the region at the distal end of the stomach that connects to the duodenum. The pylorus comprises the pyloric antrum, the pyloric canal, and the pyloric sphincter, a thickened ring of smooth muscle that controls gastric emptying.

The pyloric canal and sphincter coordinate rhythmic contractions to push chyme toward the duodenum while resisting retrograde flow. The rate of gastric emptying is influenced by the chemical composition of the chyme and hormonal signals from the gut, including gastrin and cholecystokinin, as well as neural input via the vagus nerve. Proper regulation ensures that the duodenum receives small, well-timed portions of partially digested material.

Clinical significance includes hypertrophic pyloric stenosis, a condition in infants characterized by nonbilious, projectile vomiting due to thickening of the pyloric muscle; it typically presents in the first weeks of life and is treated with pyloromyotomy. In adults, pyloric obstruction may result from peptic ulcers, inflammation, scar tissue, or neoplasms, and is evaluated with endoscopy or imaging. Treatments aim to relieve the obstruction and may involve surgical procedures such as pyloroplasty, gastric bypass, or other interventions depending on the underlying cause.

Etymology: The term derives from Greek pyloros, meaning gatekeeper, reflecting its function as the gateway between the stomach and the duodenum.