A smooth muscle of the eye, running radially in the iris that functions as a dilator. [WP,unvetted]. [ http://en.wikipedia.org/wiki/Iris_dilator_muscle ]
Synonyms: radial muscle of iris pupillary dilator muscle dilator pupillae muscle dilator pupillae musculus dilatator pupillae iris dilator muscle dilator of pupil dilator muscle of pupil
Term information
- EMAPA:35286
- UMLS:C0229190 (ncithesaurus:Dilator_Pupillae_Muscle)
- NCIT:C32463
- BTO:0001371
- FMA:49158
- MA:0001288
- Wikipedia:Iris_dilator_muscle
- SCTID:280890008
uberon_slim
It is innervated by the sympathetic system, which acts by releasing noradrenaline, which acts on alpha1-receptors. Thus, when presented with a threatening stimuli that activates the fight-or-flight response, this innervation dilates the iris, thus temporarily letting more light reach the retina
musculus dilator pupillae
dilator pupillae muscle
pupillary muscle
iris dilator
pupil dilator muscle
pupillary dilator
radiating fibers
musculus dilatator pupillae
radial muscle
pupil dilator
Term relations
- iris smooth muscle
- ectoderm-derived structure
- develops from some neurectoderm
- has muscle insertion some iris
- has muscle origin some iris
- has muscle antagonist some sphincter pupillae