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Nervous System and Endocrine > Eye > Flashcards

Flashcards in Eye Deck (10)
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1

The eye

Contains organs of visions

Covert light into nervous impulses

2

Eyelid

Protects the eye

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

3

Meibomion glands

Sebaceous glands beneath conjunctiva

4

Conjunctiva

Transparent mucous membrane

Angle formed by reflection which is the fornix

5

Lacrimal Apparatus

Lies under upper eyelid

Produces tears

Drain to naso lacrimal duct system

6

3 layers of the eye

Sclera, Urea and Retina

7

Sclera

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

8

Urea

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

9

3 separate media within eye

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

10

Retina

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