sphincter
(sfingk′tĕr )
To hear audio pronunciation of this topic, purchase a subscription or log in.
[Gr. sphinktēr, tight band]
A circular muscle constricting an orifice. In normal tonic condition, it closes the orifice, i.e., the muscle must relax to allow the orifice to open.There's more to see -- the rest of this topic is available only to subscribers.
© 2000–2025 Unbound Medicine, Inc. All rights reserved