sphincter
A ring-shaped muscle that surrounds a natural opening in the body and can open or close it by relaxing or contracting.
Last Updated
October 7, 2025
October 7, 2025
Last updated: October 7, 2025.
This article was contributed by .
Explore More
Why Exercise?
Why exercise? Exercise is powerful medicine. It is an important part of a healthy lifestyle. Exercise prevents health problems, builds strength, boosts energy, and can help you reduce stress. It ca...