English: Sequence of images diagramming the emptying of stomach chyme into the duodenum through the pyloric sphincter. As the stomach fills, signals from the stomach initiate the secretion of alkaline mucous into the duodenum. Peristaltic waves in the stomach then push chyme through the dilated pyloric sphincter into the duodenum. The pH of the small amount of acidic chyme within the duodenum then mixes with the alkaline mucous to neutralize the contents of the intestinal lumen.