Outer Fibrous Coat

Question 1

Outer fibrous coat

Answer 1

1. Conjunctiva
2. Sclera
3. Cornea

Question 2

Conjunctiva

Answer 2

Structure: a delicate mucous membrane that covers the front of the eye and lines of the eyelids
Functions:
1. It has pain receptors that reflexively cause the eyelid to close, preventing foreign bodies from entering
2. It produces lubricating mucus that prevents the eyes from dying

Question 3

Sclera

Answer 3

Structure: this tough, white inelastic layer is made up of connective tissue and covers the posterior 5/6 of the eyeball
Functions:
1. Protects the internal parts of the eyes
2. Provides points of attachment for the six extrinsic eye muscles
3. Inelastic nature helps to maintain the shape of the eye

Question 4

Cornea

Answer 4

Structure: this is a continuation of the sclera and occupies the front 1/6 of the eyeball
- it is more convex than the rest of the eyeball
- it is transparent as it has no blood vessels
- it is covered by the conjunctiva
Functions:
1. Being transparent, it allows light rays to pass through to the light-sensitive cells
2. It causes converging refraction of these light rays. It focuses the light.
3. The conjunctiva has many pain receptors which enable the eyelids to close reflexively.