Ciliary Body

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ciliary body

[¦sil·ē‚er·ē ¦bäd·ē]
A ring of tissue lying just anterior to the retinal margin of the eye.

Ciliary Body


in terrestrial vertebrates, including humans, the part of the eye that converts blood serum into the intraocular fluid that is secreted into the posterior chamber of the eye. The ciliary body forms a circle of numerous radial folds (70 to 80 in humans) on the internal surface of the eye between the iris and the retina. It consists of mesodermal stroma and two neuroepithelia. The external pigmented neuroepithelium is a continuation of the pigmented epithelium of the retina, whereas the nonpigmented internal layer, which plays a major role in the secretion of intraocular fluid, is a continuation of the retina proper.

Fibers of the zonule of Zinn are attached to the basal membrane of the ciliary folds. The amount of tension of the ligament is determined by contraction of the circular ciliary muscle situated in the stroma of the ciliary body near the place of contact with the sclera. The tension of the ciliary muscle determines the shape of the crystalline lens. The ciliary body is the most vascularized part of the eye; it is supplied by blood vessels from the systemic circulation of the iris.

Inflammation of the ciliary body is called cyclitis; inflammation of both the ciliary body and the iris is called iridocyclitis.


Stroeva, O. G. Morfogenez i vrozhdennye anomalii glaza mlekopitaiushchikh. Moscow, 1971.
Davson, H. The Physiology of the Eye, 3rd ed. Edinburgh-London, 1972.


References in periodicals archive ?
Confusing names attached to intraocular medulloepithelioma in the past have hampered effective communication and probably delayed a logical system of classification for tumors of the ciliary epithelium.
In the 1970s, Lorenz Zimmerman (5,6) proposed a system for classifying primary tumors of the ciliary epithelium, as well as the conceptual framework for understanding the cellular polymorphism of medulloepithelioma.
Free tumor cells express TGF-[beta] and VEGF, are spread via the aqueous humor between the vitreous base and ciliary epithelium for 360[degrees], migrate through the pupil where they become implanted into the iris, and cause neo vascularization of the iris.