What is the main mechanism by which the intestinal phase inhibits gastric acid secretion?
1) By releasing hormones that inhibit gastrin release
2) By promoting the release of somatostatin
3) By reducing vagal input to the stomach
4) By increasing the pH of gastric contents
E) By reducing the activity of the myenteric plexus
📝 Explanation:
The intestinal phase of gastric acid secretion is mainly responsible for inhibiting gastric secretion. This is primarily achieved through the release of hormones like secretin and cholecystokinin (CCK) in response to the presence of acidic chyme in the duodenum. These hormones act on D cells in the stomach to reduce gastrin secretion, which in turn decreases acid production by parietal cells. Additionally, the presence of food in the intestine triggers an enterogastric reflex that inhibits the vagal nerve's excitatory effects on the stomach.
MCQ