The pars plicata (also known as corona ciliaris ) (Latin: folded portion) is the folded and most anterior portion of the

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 aqueous humor is produced in the non-pigmented portion of the ciliary ...

of an eye. The ciliary body is a part of the

uvea The uvea (; derived from meaning "grape"), also called the uveal layer, uveal coat, uveal tract, vascular tunic or vascular layer, is the pigmented middle layer of the three concentric layers that make up an eye, precisely between the inne ...

, one of the three layers that comprise the

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

. The pars plicata is located anterior to the

pars plana The ''pars plana'' (also known as ''orbicularis ciliaris'' ) (Latin: flat portion) is part of the ciliary body in the uvea (or vascular tunic, the middle layer of the three layers that comprise the eye). It is about 4 mm long, located near th ...

portion of the ciliary body, and posterior to the iris. The lens

zonules The zonule of Zinn () (Zinn's membrane, ciliary zonule) (after Johann Gottfried Zinn) is a ring of fibrous strands forming a wikt:zonule#Noun, zonule (little band) that connects the ciliary body with the crystalline lens (anatomy), lens of the eye ...

that are used to control accommodation are attached to the pars plana. The pars plicata is the portion of the ciliary body that is responsible for producing

aqueous humor The aqueous humour is a transparent water-like fluid similar to blood plasma, but containing low protein concentrations. It is secreted from the ciliary body, a structure supporting the lens of the eyeball. It fills both the anterior and the po ...

, the fluid of the

anterior chamber The anterior chamber ( AC) is the aqueous humor-filled space inside the eye between the iris and the cornea's innermost surface, the endothelium. Hyphema, anterior uveitis and glaucoma are three main pathologies in this area. In hyphema, ...

. The production of too much aqueous humor, or reabsorption that occurs too slowly, can lead to increases in the pressure within the eye.

References

{{DEFAULTSORT:Pars Plicata Human eye anatomy