During the Cephalic Phase of Gastric Secretion

Question

During the cephalic phase of gastric secretion,
A) the stomach responds to distention.
B) secretin inhibits parietal and chief cells.
C) CNS sensory or cognitive activation increases neural stimulation of the stomach.
D) the intestinal reflex inhibits gastric emptying.
E) the gastroileal reflex decreases production of gastric juice.

Accepted Answer

The cephalic phase of gastric secretion is triggered by sensory or cognitive activation of the CNS, which increases neural stimulation of the stomach through the vagus nerve. This phase accounts for about 30% of acid secretion during a meal. Distention of the stomach, which is mentioned in option A, triggers the gastric phase of secretion. Secretin, which is mentioned in option B, is a hormone released by the small intestine that inhibits gastric acid secretion. The intestinal reflex mentioned in option D is part of the enterogastric reflex, which inhibits gastric emptying when the small intestine is distended. The gastroileal reflex, mentioned in option E, is a reflex that increases peristalsis in the small intestine and promotes the emptying of its contents into the colon; it has no effect on gastric juice production.