Ciliary body Ciliary body The ciliary body is a part of the eye that includes the ciliary muscle, which controls the shape of the lens, and the ciliary epithelium, which produces the aqueous humor. The vitreous humor is produced in the non-pigmented portion of the ciliary body. The ciliary body is part of the uvea, the layer of tissue that delivers oxygen and nutrients to the eye tissues. The ciliary body joins the ora serrata of the choroid to the root of the iris. The ciliary body is a ring-shaped thickening of tissue inside the eye that divides the posterior chamber from
Iris sphincter muscle reflex) or during accommodation. In lower animals, the muscle cells themselves are photosensitive causing iris action without brain input. It is controlled by parasympathetic fibers of the muscarinic acetylcholine receptor (M3) that originate from the Edinger-Westphal nucleus, travel along the oculomotor nerve (CN III), synapse in the ciliary ganglion, and then enter the eye via the short ciliary nerves.. The short ciliary nerves then run forward and pierce the sclera at the back of the eye, traveling between the sclera and the choroid to innervate the iris sphincter muscle. Iris sphincter muscle The iris sphincter muscle (pupillary sphincter, pupillary constrictor,