part_of part of part of has part has part has_part develops_from develops from contributes to morphology of material entity material entity multi-tissue structure ciliary muscle ciliary body http://upload.wikimedia.org/wikipedia/commons/1/1e/Schematic_diagram_of_the_human_eye_en.svg CALOHA:TS-0694 NCIT:C12345 ocular ciliary body ciliary bodies SCTID:263340007 GAID:916 UMLS:C0008779 MESH:D002924 FMA:58295 XAO:0000186 Wikipedia:Ciliary_body VHOG:0000102 AAO:0010341 MA:0000264 The thickened portion of the vascular tunic, which lies between the choroid and the iris, composed of ciliary muscle and ciliary processes. uberon corpus ciliare EV:0100346 EMAPA:19065 anterior uvea The eye of the adult lamprey is remarkably similar to our own, and it possesses numerous features (including the expression of opsin genes) that are very similar to those of the eyes of jawed vertebrates. The lamprey's camera-like eye has a lens, an iris and extra-ocular muscles (five of them, unlike the eyes of jawed vertebrates, which have six), although it lacks intra-ocular muscles. Its retina also has a structure very similar to that of the retinas of other vertebrates, with three nuclear layers comprised of the cell bodies of photoreceptors and bipolar, horizontal, amacrine and ganglion cells. The southern hemisphere lamprey, Geotria australis, possesses five morphological classes of retinal photoreceptor and five classes of opsin, each of which is closely related to the opsins of jawed vertebrates. Given these similarities, we reach the inescapable conclusion that the last common ancestor of jawless and jawed vertebrates already possessed an eye that was comparable to that of extant lampreys and gnathostomes. Accordingly, a vertebrate camera-like eye must have been present by the time that lampreys and gnathostomes diverged, around 500 Mya.[well established][VHOG] UBERON:0001775 BTO:0000260 http://braininfo.rprc.washington.edu/centraldirectory.aspx?ID=1571 neurectoderm ectoderm-derived structure ciliary processes anterior uvea