Also found in: Thesaurus, Medical, Encyclopedia, Wikipedia.
Related to sphincter: sphincter muscle, Sphincter of Oddi, sphincterotomy, sphincter spasm, Esophageal sphincter
A ringlike muscle that normally maintains constriction of a body passage or orifice and that relaxes as required by normal physiological functioning.
[Late Latin sphinctēr, from Greek sphinktēr, from sphingein, to bind tight.]
(Anatomy) anatomy a ring of muscle surrounding the opening of a hollow organ or body and contracting to close it
[C16: from Late Latin, from Greek sphinkter, from sphingein to grip tightly]
a circular band of voluntary or involuntary muscle that encircles and closes an orifice of the body or one of its hollow organs.
[1570–80; < Late Latin < Greek sphinktḗr=sphing-, base of sphíngein to hold tight + -tēr agent suffix]
A ring-shaped muscle that encircles an opening or passage in the body. Contraction and relaxation of a sphincter closes and opens the passage.
A ring-shaped muscle that contracts to close an orifice.
Switch to new thesaurus
|Noun||1.||sphincter - a ring of muscle that contracts to close an opening|
physiological sphincter - a sphincter that is not recognizable at autopsy because its resting arrangement cannot be distinguished from adjacent tissue
musculus sphincter urethrae, urethral sphincter - a striated sphincter muscle that constricts the urethra
bladder sphincter, musculus sphincter vesicae - the sphincter muscle of the urinary bladder; made up of a thickened muscular layer of bladder around the urethral opening
musculus sphincter ductus choledochi - the smooth muscle sphincter of the common bile duct
musculus sphincter ductus pancreatici - the smooth muscle sphincter of the main pancreatic duct