EYE

Question 1

function of vitreous chmaber

Answer 1

• nourishes eye
• refracts light
• maintains shape of eye

Question 2

function of aqueous

Answer 2

nourishes the eye through diffusion of nutrients and o2
- refracts light and maintains shape of eye

Question 3

what forms neural retina

Answer 3

optic vesicle to optic cup

Question 4

what forms lens

Answer 4

lens placode to lens pit

Question 5

layers of the sclera

Answer 5

• fibrous
• vascular
• retinal

Question 6

function of fibrous layer in the sclera

Answer 6

provides shape and support

Question 7

what is the fibrous layer of sclera made of

Answer 7

sclera and cornea

Question 8

what does the bowmans membrane support

Answer 8

corneal epithelium

Question 9

list the 6 layers of the cornea

Answer 9

• basement membrane
• bowmans membrane
• collagen fibrils
• ketaocytes
• duas layer
• descemets membrane

Question 10

descemets membrane

Answer 10

supports endothelium

Question 11

what does the vascular layer of uvea consists of

Answer 11

choroid
iris
ciliary body

Question 12

function of irisi

Answer 12

pigmentation defines eye colour and controls the size of pupils to regulate levels of light

Question 13

what is pupil size (iris) controlled by

Answer 13

circular and radial muscle fibres

Question 14

what is ciliary muscles made up of

Answer 14

equatorial circular fibres
- reticular radial fibres
- meridinal longitudinal fibres

Question 15

function of lens

Answer 15

transmits and focusses light onto the retina

Question 16

list the two. layers of the retina

Answer 16

• neural layer
• pigmented layer

Question 17

what does the neural layer of the retina have

Answer 17

photoreceptors (light detecting cells)

Question 18

what does the pigmented layer of the retina have

Answer 18

attaches to coroid and supports neural cells, prevents internal refraction of light

Question 19

how is the retina viewed

Answer 19

fundoscopy

Question 20

what can we see in the retina

Answer 20

optic disc
macula lutea
fovea centralis

Question 21

light entering the eye is focused by

Answer 21

cornea and the lens tohit the photosensitive rods and cones of the retina

Question 22

what is cataracts

Answer 22

loss of lens transparency
loss of light focusing ability
focus 2/3 cornea, 1/3 lens

Question 23

what causes the loss of lens transparency

Answer 23

change to lens cell organisation
altered lens cell morphology
diabetes
age
family history etc

Question 24

3 types of cataracts

Answer 24

• nuclear sclerotic
• cortical spoking
• subscapular > anteiror or posterior

Question 25

what is nuclear sclerotic cataract

Answer 25

most common age related one impacts the centre of the lens > hardening and discolouration BROWN NUCLEUS

Question 26

how does cortical spoking cataract start

Answer 26

white streaks on rim of lens swelling of cortex

Question 27

what does cortical spoking cataract causes

Answer 27

light scattering glare and halo effect

Question 28

what is posterior scapular cataract more common in

Answer 28

diabetic peoope and steroid users

Question 29

treatments for all types of cataract

Answer 29

- laser assisted - phacoemulsificaton - insertion of intraocular lens

Question 30

what is the neural layer of the eye

Answer 30

retinal

Question 31

how many layers in the neural retinal layer of the eye

Answer 31

2 neural pigmented

Question 32

list the structures of the uvea

Answer 32

iris choroid ciliary body

Question 33

function of ciliary body

Answer 33

accomodation

Question 34

what is needed for accomodation

Answer 34

ciliary body and zonule fibres

Question 35

explain accomodation with its relationship to ciliary body and zonule fibres

Answer 35

ciliary body contracts > causing the zonule tensions to relax > lens becomes rounded tension by zonule fibres extending from ciliary body to lens > lens become flatter

Question 36

what is the pupil size of the iris controlled by

Answer 36

circular and radial muscle fibres

Question 37

what does ciliary body produce

Answer 37

aqueous humour by pigmented epithelia