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 …

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 …

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, …

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.

Aug 21, 2025 · A sphincter is a circular muscle that functions like a natural valve in the body. These muscles control the passage of substances through various openings or tubes.

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

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

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 …

May 2, 2025 · The sphincter is a muscular ring, a crucial part of the body's anatomy. Learn about its function, types, and their role in maintaining health.

A ring-shaped muscle that relaxes or tightens to open or close a passage or opening in the body. Examples are the anal sphincter (around the opening of the anus) and the pyloric sphincter (at …