Which sphincter regulates passage from the stomach to the small intestine?

Which sphincter regulates passage from the stomach to the small intestine?

• A. Lower esophageal sphincter
• B. Ileocecal valve
• C. Anal sphincter
• D. Pyloric sphincter

Answer: (D)

The key idea is the valve that governs how partly digested food leaves the stomach and enters the small intestine. That valve, the pyloric sphincter, sits at the outlet of the stomach and controls gastric emptying into the duodenum. It opens to let small amounts of chyme pass through and then contracts to regulate the flow, helping coordinate digestion and prevent backflow. By comparison, the lower esophageal sphincter sits between the esophagus and stomach and prevents reflux into the esophagus, the ileocecal valve sits between the ileum and the cecum, and the anal sphincter controls the passage of stool. Thus, the pyloric sphincter is the structure that regulates passage from the stomach to the small intestine.

The key idea is the valve that governs how partly digested food leaves the stomach and enters the small intestine. That valve, the pyloric sphincter, sits at the outlet of the stomach and controls gastric emptying into the duodenum. It opens to let small amounts of chyme pass through and then contracts to regulate the flow, helping coordinate digestion and prevent backflow.

By comparison, the lower esophageal sphincter sits between the esophagus and stomach and prevents reflux into the esophagus, the ileocecal valve sits between the ileum and the cecum, and the anal sphincter controls the passage of stool. Thus, the pyloric sphincter is the structure that regulates passage from the stomach to the small intestine.