Which structures are part of the uveal tract?

The uveal tract, also known as the uvea, is a significant part of the eye responsible for nourishing the retina and consists of three primary structures: the iris, ciliary body, and choroid. Each of these components plays a vital role in eye function and physiology.

The iris is the colored part of the eye that controls the size of the pupil and, consequently, the amount of light entering the eye. The ciliary body is crucial for accommodating the lens to focus on objects at various distances, as well as for producing aqueous humor, the fluid that maintains intraocular pressure and nourishes the eye. The choroid is a vascular layer that lies between the retina and the sclera, providing oxygen and nutrients to the outer layers of the retina and helping to absorb excess light.

In contrast, the other options do not accurately describe the uveal tract. The retina, macula, lens, cornea, sclera, conjunctiva, lacrimal gland, and eyelid do not form part of the uvea and serve different functions in the anatomy and physiology of the eye. Their roles are important, but they do not belong to the uveal tract specifically.