WEEK 6: Special senses of the eye

Question 1

what are the 3 layers of the eye?

Answer 1

corneoscleral coat (outer)
vascular coat (uvea)
retina (inner)

Question 2

what is the corneoscleral layer?

Answer 2

outer fibrous layer of the eye:
- cornea is the transparent section
- sclera is the white portion

Question 3

what is the vascular coat (uvea) of the eye?

Answer 3

middle layer contains:
- choroid
- iris
- ciliary body

Question 4

what is the retina?

Answer 4

inner layer of the eye

Question 5

what are the 3 layers to the sclera? What are their properties?

Answer 5

• episclera - thick fibrous layer with dense connective tissue
• sclera proper - flat collagen bundles
• lamina cribosa - pigmented, allows for entry/exit of nerves and vessels

Question 6

what are the five layers of the cornea? (outer to inner layer)

Answer 6

1. corneal epithelium
2. Bowman’s membrane
3. corneal stroma
4. Descemet’s membrane
5. corneal endothelium

Question 7

what is the function of the cornea?

Answer 7

refraction of light
structural barrier and protects against infections

Question 8

what 2 muscles make up the iris?

Answer 8

dilator pupillae
sphincter pupillae

Question 9

2 muscles make up the iris. What do they lay underneath?

Answer 9

dilator pupillae - under is sympathetic nervous system
sphincter pupillae - under parasympathetic ns

Question 10

what gives eye colour?

Answer 10

pigmentation in the iris

Question 11

what is the ciliary body?

Answer 11

thickened anterior body between iris and choroid

Question 12

what is the function of the ciliary muscle?

Answer 12

changes the shape of the lens when the eye focuses
secretion of aqueous humour

Question 13

what is the segment called from the cornea to lens?

Answer 13

anterior segment

Question 14

where is the post chamber?

Answer 14

behind the iris to lens

Question 15

what is the section named between the iris and cornea?

Answer 15

anterior chamber

Question 16

what is the canal of schlemm (scleral venous sinus)

Answer 16

little opening which allow aq humour to escape.
Allows decrease in pressure of the eye so optic nerve is not affected.

Question 17

what is the vitreous body?

Answer 17

transparent jelly-like substance in posterior segment of the eye.
maintains shape of the eye and keeps retina in place.

Question 18

what are the 2 layers of the retina?

Answer 18

neural retina (retina proper)
retina pigment epithelium (RPE)

Question 19

where does retinal detachment occur?

Answer 19

outer segments of rods and cones

Question 20

what vision are rods and cones for?

Answer 20

rods - black and white
cones - colour vision

Question 21

what’s the clinical correlation of the vitreous body?

Answer 21

composition can change with age resulting in vitreous detachment and retinal detachment

Question 22

what’s the clinical correlation of rods?

Answer 22

night blindness

Question 23

what’s the clinical correlation of cones?

Answer 23

colour blindness

Question 24

how many rods in eye?

Answer 24

~120 million

Question 25

how many cones in eye?

Answer 25

~7 million

Question 26

what is the function of the RPE?

Answer 26

absorption of light
active in visual pigment pathways
major component of blood-barrier via tight junctions

Question 27

what is the fovea centralis?

Answer 27

area of largest density of cones.