Question

1. What is the function associated with each of the following structures?

1. Retina
2. Fibrous tunic
3. Choroid layer
4. Suspensory ligament
5. Optic nerve
6. Lens
7. Cornea

Answer 1

a. The retina is the part of the eye that contains the photoreceptors.The retina absorbs the light that falls on it with the help of the photoreceptors and coverts it into the visual sensory signals.

b.The fibrous tunic of the eye is the outer part that consists of the sclera and the cornea.

The functions of the fibrous tunic are

• protection and mechanical support to the eye.
• Assists in the focusing of the eye
• Provides site of attachment for the extrinsic eye muscles

c.The functions of the choroid layer which is the middle vascular layer of the eye are

• provides blood supply to the retinal layers
• Regulated the heat inside the eyeball
• control of the intra occular pressure
• The black pigment absorbs the light to prevent it scattering inside the eye

d.The suspensory ligaments of the eyeball maintains the stability of the eye lens,helps to control the size and shape of the lens and helps it to focus.

e.The optic nerve is the second cranial nerve and the function of the optic nerve is to transmit the impulses produces by the retina to the visual cortex of the brain.

f.The eye lens is the structure that allows the image to be focussed correctly on the retina.The function is the accommodation of the eye.

g.The cornea is the transparent layer that covers the front portion of the eye.

The functions of cornea are

• It is an important refractive medium of the eye
• It protects the eye from harmful substances including germs,UV light rays etc..
• The transparent nature of the cornea allows the passage of light into the eye