Ciliary body

Ciliary body
Anterior part of the human eye, with ciliary body near bottom.
Details
Artery	long posterior ciliary arteries
Identifiers
Latin	corpus ciliare
MeSH	A09.371.894.280
Dorlands /Elsevier	c_56/12260436
TA	A15.2.03.009
FMA	58295
Anatomical terminology []

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 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 the vitreous body. It contains the ciliary muscle, vessels, and fibrous connective tissue. Folds on the inner ciliary epithelium are called ciliary processes, and these secrete aqueous humor into the posterior chamber. The aqueous humor then flows through the pupil into the anterior chamber.

The ciliary body is attached to the lens by connective tissue called the zonular fibers (fibers of Zinn). Relaxation of the ciliary muscle puts tension on these fibers and changes the shape of the lens in order to focus light on the retina.

The inner layer is transparent and covers the vitreous body, and is continuous from the neural tissue of the retina. The outer layer is highly pigmented, continuous with the retinal pigment epithelium, and constitutes the cells of the dilator muscle. This double membrane is often considered continuous with the retina and a rudiment of the embryological correspondent to the retina. The inner layer is unpigmented until it reaches the iris, where it takes on pigment. The retina ends at the ora serrata.