Question

The exposed transparent region of eyeball represents
A. Uvea
B. Cornea and conjunctiva
C. Fibrous coat
D. Cornea

Answer 1

Hint: The human eyes are part of the sensory nervous system. They are the organs related to vision and react to the light. The structure of the eye is complex, and it is formed by the association of muscles, lens and photosensitive cells. In humans, the eyes are two in number and are situated in two hollow cavities which are known as orbits.

Complete answer:
The eyes in humans are situated in the bony orbits that are present in the skull. The eyes are moved through the extraocular muscles which remain directly connected to the eyes. They are six in number. The front portion of the eye that is visible, is whitish in color and is known as sclera. In this portion, a colored iris and the pupil is present. The sclera forms the external layer of the eye and along with the cornea it forms the fibrous layer or the fibrous coat. These parts of the eye are covered with a thin transparent covering called the conjunctiva. The major function of conjunctiva is the protection of the cornea which is a delicate portion of the eye.

The cornea is transparent and more curved in structure. The cornea is the anterior portion of the eye and absorbs oxygen present in the air. It is devoid of blood supply. It is linked to the larger posterior segment. It is composed of the vitreous, retina, choroid and the outer sclera. The cornea connects with the sclera through an area known as the limbus.

The uvea is the middle layer and it consists of choroid, ciliary body, pigmented epithelium and the iris. It is also known as the vascular tunic. The uvea provides shape to the eye and supports the deeper structures. The innermost portion of the eye is known as the retina and it gets oxygen supply from the blood vessels of the choroid and the retinal vessels.

Hence, the correct answer is option (B).

Note: The structure and working of the human eye is complex in nature and it is brought about by the combined action of a number of subunits. The exposed region of the eye is transparent, and it is represented by the cornea and conjunctiva. The cornea does not receive any blood and it is transparent. The conjunctiva is a transparent covering which protects the delicate cornea.