Eye

Question 1

The eye

Answer 1

Contains organs of visions

Covert light into nervous impulses

Question 2

Eyelid

Answer 2

Protects the eye

Has nicitating membrane (3rd eyelid) and distributes tear film

Question 3

Meibomion glands

Answer 3

Sebaceous glands beneath conjunctiva

Question 4

Conjunctiva

Answer 4

Transparent mucous membrane

Angle formed by reflection which is the fornix

Question 5

Lacrimal Apparatus

Answer 5

Lies under upper eyelid

Produces tears

Drain to naso lacrimal duct system

Question 6

3 layers of the eye

Answer 6

Sclera, Urea and Retina

Question 7

Sclera

Answer 7

Outer layer, white part

Helps maintain shape of eye and have extra ocular muscles insert in here which control movement

Sclera and cornea meet at limbus

Question 8

Urea

Answer 8

Middle layer and is vascular pigmented and contains

Choroid - area of light reflecting cells with tapetim lucidem that reflects light back onto retina dim light conditions

Iris - vascular, contraction/relaxation of smooth muscle alters pupils size and controls amount of light entering the eye

Ciliary body - contraction alters shape of lens and allow eye to focus on objects at different distances

Question 9

3 separate media within eye

Answer 9

Aqueous humour - watery fluid that provides nutrients to lens. In healthy animal it’s continuously produced and drained

Vitreous humour - maintains shape, semi fluid transparent gel

Lens - biconvex transparent structure, attached to colliery body by suspending ligament and focuses light into the retina

Question 10

Retina

Answer 10

Inner layer

2 layers of photoreceptors:
Rods - for night vision responds to dim light and black and white
Cones - respond to colour

Both convert light to nervous impulses which travel to optic disc to cerebral hemisphere where impulses are interpreted