Question

irritation of the digestive tract lining is the stimulus, and the response is the reversal of the normal action of smooth muscle to eject the contents of the digestive tract. this describes which visceral reflex?

Explanation:

• Gastric and intestinal reflexes: These are related to normal digestive functions like peristalsis for digestion and absorption, not ejection due to irritation.
• Vomiting reflex: When the digestive tract lining (e.g., in the stomach) is irritated (by toxins, infections etc.), the smooth muscle action reverses (retroperistalsis) to eject the contents (vomiting). This matches the description.
• Vasomotor reflexes: Concerned with blood vessel diameter and blood pressure regulation, not digestive tract content ejection.
• Defecation reflex: Involves elimination of feces from the rectum, a normal process (not due to irritation - induced ejection of general digestive tract contents).

Answer:

Vomiting reflex