Sphincter - Wikipedia
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. …
Sphincters: What They Are, Locations & Function
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 …
Types and Function of Sphincters in the Body - Verywell Health
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 | Esophageal, Gastrointestinal & Urogenital
sphincter muscle, any of the ringlike muscles surrounding and able to contract or close a bodily passage or opening.
Sphincters: Functions, Weakness & Treatment
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.
What Is a Sphincter? Types, Function, and Common Problems
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 …
SPHINCTER Definition & Meaning - Merriam-Webster
The meaning of SPHINCTER is an annular muscle surrounding and able to contract or close a bodily opening.
The Sphincter Muscle: Understanding Its Function And Anatomy
Jul 2, 2025 · The sphincter muscle is a ring-like muscle that controls the opening and closing of body passages. Learn about its anatomy and functions.
What is a Sphincter and its Types? Explained for Health
Oct 11, 2025 · A sphincter is a circular or ring-like muscle that acts as a valve to control the flow of substances through a bodily passage. By contracting, a sphincter can close an opening or passage, …
What Is a Sphincter and What Does It Do? - Biology Insights
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.