What is uvial tract?!
Question:
What is uvial tract?
Answers:
Well hun.... The Uveal Tract consists of the choroid, ciliary body and iris. It is the middle vascular layer of the eye and is protected by the cornea and sclera. It contributes blood supply to the retina.
Iris:
is the anterior extension of the ciliary body. It presents as a flat surface with a centrally situated round aperture the pupil. Within the stroma of the iris are the sphincter and dilator muscles. The two heavily pigmented layers on the posterior surface of the iris represent anterior extensions of the neuroretina and retinal pigment epithelium. The iris controls the amount of light entering the eye. Pupillary size is principally determined by balance between constriction due to parasympathetic activity transmitted via the third cranial nerve and dilation due to sympathetic activity.
The ciliary body :
roughly triangular in cross section extends forward from the anterior end of the choroid to the root of the iris (about 6mm). Composed mainly of capillaries and veins that drain through the vortex veins. The ciliary processes and their covering ciliary epithelium are responsible for the formation of aqueous.
The choroid:
Posterior segment of the uveal tract, between the retina and the sclera. It is composed of three layers of choroidal blood vessels: Large, medium and small. The aggregate of choroidal blood vessels serves to nourish the outer portion of the underlying retina.