part_of part of part of develops from develops from has muscle origin has muscle origin has muscle insertion has muscle insertion has muscle antagonist system muscle of iris sphincter pupillae http://upload.wikimedia.org/wikipedia/commons/2/2f/Gray878.png EMAPA:35788 FMA:49157 BTO:0000656 UBERON:0001607 musculus sphincter pupillae Wikipedia:Iris_sphincter_muscle UMLS:C0229189 uberon M. sphincter pupillae NCIT:C33586 sphincter muscle of pupil MA:0001289 A sphincter muscle that is part of the iris. SCTID:280889004 iris sphincter muscle dilatator pupillae iris neurectoderm iris smooth muscle sphincter muscle smooth muscle sphincter