The role of a sphincter is to
A) control the passage of materials.
B) create a churning motion.
C) propagate peristalsis.
D) absorb excess water from feces.
E) do more than one of these.

Question

Quizplus · Accepted Answer

A sphincter is a muscular ring that surrounds a tubular structure, such as a muscle or a duct, and regulates the flow of materials through it. For example, the anal sphincter controls the passage of feces through the anus, while the esophageal sphincter controls the flow of food and liquids into the stomach. Therefore, the role of a sphincter is primarily to control the passage of materials.

The Role of a Sphincter Is to