SPHINCTER MUSCLE

Pronunciation (US):

(GB):

 Dictionary entry overview: What does sphincter muscle mean? 

• SPHINCTER MUSCLE (noun)
  The noun SPHINCTER MUSCLE has 1 sense:

1. a ring of muscle that contracts to close an opening

  Familiarity information: SPHINCTER MUSCLE used as a noun is very rare.

 Dictionary entry details 

• SPHINCTER MUSCLE (noun)

Sense 1

Meaning:

A ring of muscle that contracts to close an opening

Classified under:

Nouns denoting body parts

Synonyms:

anatomical sphincter; sphincter; sphincter muscle

Hypernyms ("sphincter muscle" is a kind of...):

muscle; musculus (one of the contractile organs of the body)

Hyponyms (each of the following is a kind of "sphincter muscle"):

physiological sphincter (a sphincter that is not recognizable at autopsy because its resting arrangement cannot be distinguished from adjacent tissue)

anal sphincter; musculus sphincter ani; sphincter ani (the sphincter muscle of the anus)

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)

musculus sphincter pupillae; pupillary sphincter (a ring of smooth muscle surrounding the iris)

musculus sphincter pylori; pyloric sphincter; pyloric valve (the sphincter muscle of the pylorus that separates the stomach from the duodenum)

 Context examples 

When administered in the conjunctiva, this agent binds to alpha-adrenergic receptors in the iris sphincter muscle, resulting in vasoconstriction, a decrease in the production of aqueous humor, and a lowering of intraocular pressure.

(Epinephrine Hydrochloride, NCI Thesaurus)

Administered in the eye, cyclopentolate hydrochloride blocks the acetylcholine receptor in the sphincter muscle of the iris and the ciliary muscle, thereby preventing contraction.

(Cyclopentolate Hydrochloride, NCI Thesaurus)

Administered as an ophthalmic solution, this drug stimulates the cholinoceptors in the sphincter muscle of the iris, causing the pupil to constrict.

(Acetylcholine Chloride, NCI Thesaurus)

This causes contraction of the iris sphincter muscle (producing miosis) and the ciliary muscle (affecting the accommodation reflex).

(Demecarium, NCI Thesaurus)