Iris sphincter muscle

Iris sphincter muscle
Iris, front view. (Muscle visible but not labeled.)
The upper half of a sagittal section through the front of the eyeball. ("Sphincter of pupil" labeled near bottom-center.)
Details
OriginEncircles iris[1]
InsertionEncircles iris[1]
ArteryLong posterior ciliary arteries
NerveShort ciliary nerves
ActionsConstricts pupil
AntagonistIris dilator muscle
Identifiers
Latinmusculus sphincter pupillae
TA98A15.2.03.029
TA26762
FMA49157
Anatomical terms of muscle

The iris sphincter muscle (pupillary sphincter, pupillary constrictor, circular muscle of iris, circular fibers) is a muscle in the part of the eye called the iris. It encircles the pupil of the iris, appropriate to its function as a constrictor of the pupil.

The ciliary muscle, pupillary sphincter muscle and pupillary dilator muscle sometimes are called intrinsic ocular muscles[2] or intraocular muscles.[3]

  1. ^ a b Gest, Thomas R; Burkel, William E. (2000). "Anatomy Tables - Eye". Medical Gross Anatomy. University of Michigan Medical School. Archived from the original on 2010-05-26.{{cite web}}: CS1 maint: unfit URL (link).
  2. ^ Kels, Barry D.; Grzybowski, Andrzej; Grant-Kels, Jane M. (March 2015). "Human ocular anatomy". Clinics in Dermatology. 33 (2): 140–146. doi:10.1016/j.clindermatol.2014.10.006. PMID 25704934.
  3. ^ Ludwig, Parker E.; Aslam, Sanah; Czyz, Craig N. (2024). "Anatomy, Head and Neck: Eye Muscles". StatPearls. StatPearls Publishing. PMID 29262013.

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