Term Name: sphincter muscle
Synonyms: circular muscle, sphincter
Definition: A structure, usually a circular muscle, that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning.
Ontology: Cell Ontology [UBERON:0004590]

Relationships
has parts: sphincter associated smooth muscle cell
is a type of: muscle organ
has subtype: anal sphincter cloacal sphincter esophageal sphincter gastroesophageal sphincter gastrointestinal sphincter ileocecal valve pouch sphincter pyloric sphincter smooth muscle sphincter sphincter of hepatopancreatic ampulla sphincter pupillae striated muscle sphincter urethral sphincter vaginal sphincter