Baroreceptors in the GI tract detect what type of stimulus?

• A. Chemical contents in the digestive system.
• B. Temperature changes in the bloodstream.
• C. Pressure in the surrounding abdominal cavity.
• D. Stretch in the walls of the digestive tract.

Answer: (D)

Baroreceptors in the GI tract respond to stretch of the organ walls. When contents distend the stomach or intestines, the walls stretch and these mechanosensitive receptors send signals that help regulate motility and secretions to manage digestion. This is distinct from detecting chemical contents (chemoreceptors) or temperature (thermoreceptors); external pressure on the abdomen isn’t the stimulus these receptors monitor. The key idea is that luminal distension, i.e., stretch of the GI wall, is what triggers their response.