Question

Cornea transplant in humans is almost never rejected. Because
A. It is composed of enucleated cells.
B. It is a non-living layer.
C. Its cells are least penetrable by bacteria.
D. It has no blood supply.

Answer 1

Hint:
The cornea is the transparent part which covers the eye’s front portion. Almost all of the light entering the eye is focused by the cornea. It covers the iris, pupil, and anterior chamber of the eye, which is filled with fluid.

Complete step by step answer:
The cornea's main job is to refract or bend any light that strikes it. It is made up of proteins and cells. It is a non-vascular tissue because, unlike any other human tissue, it lacks blood vessels. Because blood vessels may cause the cornea to become cloudy, impair its ability to properly reflect light, and potentially impair vision. One of the most crucial aspects of any organ (vascular) transplantation is the proper compatibility and matching of the donor and the recipient. This matching includes things like blood group matching. Any mismatch could have negative or even fatal effects. However, if it were done for any non-vascular tissue, then such exact donor-recipient matching would not be necessary. The same is true for corneal transplants. The cornea has no blood vessels at all. Anyone who needs a cornea can get one from anyone else. In comparison to other organ transplants, corneal transplants are therefore significantly simpler and more successful. So since there are no nerves, there is no blood supply in the cornea which makes it easy for a recipient to take cornea from any donor.
Hence, the right option is It has no blood supply.

Option ‘D’ is correct

Note:
Because there isn't a blood artery to nourish the cornea, aqueous humour and tears from the anterior chamber fill this role. Any tiny abrasion or scrape on the cornea can be quickly repaired. A cornea transplant (also known as a keratoplasty) can repair a damaged or diseased cornea, improve its look, and restore vision.