Sep 3, 2025 · Sphincters are circular-shaped muscles that open and close to control the flow of food, air, bile, pee and poop through your body. When a sphincter is relaxed, a substance can easily flow …

A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and relaxes as required by normal physiological functioning. Sphincters are found in many animals.

Dec 8, 2025 · Sphincters are muscles that control the flow of substances in the body. There are over 60 types of sphincters found throughout the digestive tract, urinary tract, blood vessels, and eyes. The …

sphincter muscle, any of the ringlike muscles surrounding and able to contract or close a bodily passage or opening.

Oct 10, 2024 · The internal anal sphincter is involuntary, while the external anal sphincter is under voluntary control. Together, they maintain continence and allow for controlled defecation.

Jan 6, 2026 · A sphincter is a ring-shaped muscle that surrounds and guards a natural passage or opening within the body. These muscular structures function as biological valves, regulating the flow …

Four main sphincter muscles along the alimentary canal aid in digestion: the cardiac sphincter, the pyloric sphincter, and two anal sphincters. Other sphincters are found in the iris of the eye, the bile …

The meaning of SPHINCTER is an annular muscle surrounding and able to contract or close a bodily opening.

May 10, 2025 · A sphincter is a ring-like or circular muscle that maintains constriction of a body passage or orifice and relaxes as required by normal physiological functioning.

Explore the anatomy, types, and functions of sphincters in the human body.