question_answer

Cornea is covered externally by a thin transparent membrane, which is

A)                  sclerotic                             

B)                  conjunctiva

C)                  choroid                               

D)                  None of these

Correct Answer: B

Solution :

                 Conjunctiva is a delicate membrane that covers cornea and lines the inside of the eyelid of a vertebrate eye. It is kept clean by secretion of lacrimal (tear) gland and the reflex blink mechanism. Sclerotic is the tough external layer of vertebrate eye. At the front of eye, it is modified to form the cornea. It is made up of fibrous connective tissue. It is also known as fibrous tunic and is non-vascularised. Choroid is the middle layer of eyeball. It occurs in main part of eyeball adhered to the sclerotic. It is formed of a highly vascular soft connective tissue containing few fibres, a dense network of blood capillaries and numerous branched pigment cell.