What is the name of the sphincter that prevents stomach contents from backflowing into the esophagus?

Prepare for your Anatomy and Physiology II Exam with our comprehensive exam resources. Utilize flashcards, multiple choice questions with hints, and detailed explanations. Boost your readiness for success!

Multiple Choice

What is the name of the sphincter that prevents stomach contents from backflowing into the esophagus?

The barrier that prevents stomach contents from backflowing into the esophagus is the lower esophageal sphincter—the ring of smooth muscle at the junction where the esophagus meets the stomach. It maintains a baseline tone to keep the passage closed, tightening to block reflux, and it relaxes transiently only to allow a swallow to pass into the stomach before tightening again. If this barrier weakens or relaxes inappropriately, acid from the stomach can reflux into the esophagus, leading to symptoms like heartburn. The other sphincters regulate different parts of the GI tract: the pyloric sphincter sits between the stomach and the duodenum to control gastric emptying; the Sphincter of Oddi controls bile and pancreatic juice entry into the duodenum; and the internal anal sphincter helps maintain continence at the rectal outlet.

The barrier that prevents stomach contents from backflowing into the esophagus is the lower esophageal sphincter—the ring of smooth muscle at the junction where the esophagus meets the stomach. It maintains a baseline tone to keep the passage closed, tightening to block reflux, and it relaxes transiently only to allow a swallow to pass into the stomach before tightening again. If this barrier weakens or relaxes inappropriately, acid from the stomach can reflux into the esophagus, leading to symptoms like heartburn.

The other sphincters regulate different parts of the GI tract: the pyloric sphincter sits between the stomach and the duodenum to control gastric emptying; the Sphincter of Oddi controls bile and pancreatic juice entry into the duodenum; and the internal anal sphincter helps maintain continence at the rectal outlet.

More practice questions