Which phase of gastric secretion is triggered by food ingestion?

The gastric phase of gastric secretion occurs after food has been ingested and is primarily characterized by the stimulation of gastric secretion in response to the presence of food in the stomach. This phase is initiated when food distends the stomach, which activates stretch receptors and stimulates the release of gastric secretions that include gastric acid and digestive enzymes.

During the gastric phase, the presence of proteins in the stomach also plays a critical role. The digestion of proteins stimulates the release of the hormone gastrin, which further promotes gastric acid secretion and enhances digestive activity. This phase is crucial for effectively breaking down food and aiding in the digestion process.

In contrast, the cephalic phase occurs before food enters the stomach, where digestive processes are initiated by the sight, smell, and thought of food. The nervous phase refers to the initial stimulation of gastric secretion by the nervous system. The intestinal phase is engaged once food begins to leave the stomach and enter the small intestine, regulating the flow of chyme and inhibiting gastric secretions. Each phase has its distinct purpose, but the gastric phase is specifically activated by the actual intake and presence of food in the stomach.