Question

The cephalic phase of gastric secretion occurs?

• A. On food entering the stomach
• B. On food entering the intestine
• C. On seeing food
• D. On stress

Hint:

Cephalic means head; this vagal phase fires on sight, smell, and thought of food.

Answer 1

The Correct Option is C

Step 1: Gastric secretion is divided into three phases: cephalic, gastric, and intestinal. The cephalic phase begins even before food reaches the stomach, while the food is being seen, smelled, thought about, or tasted.

Step 2: This phase is mediated by the vagus nerve. Sensory and higher brain inputs stimulate the dorsal motor nucleus of the vagus, which drives the parietal cells to secrete acid and the chief cells to secrete pepsinogen, and also releases gastrin. The greater the appetite, the stronger this response. Therefore option (c), on seeing food, is correct.

Step 3: Option (a), food entering the stomach, describes the gastric phase, triggered by distension and the products of protein digestion. Option (b), food entering the intestine, describes the intestinal phase.

Step 4: Option (d), stress, is not a defined phase of gastric secretion, so it is incorrect.