Topic 8.4

Question 1

Fibrous layer of the eye

Answer 1

Sclera + cornea

Question 2

What is macula lutea?

Answer 2

Zone with high density of photoreceptors and fovea centralis in the middle

Question 3

What is the zonula of the eye?

Answer 3

Connection between ciliaris and lens

Question 4

Type of vision of rods

Answer 4

Scotopic vision

Question 5

Type of vision of cones

Answer 5

Photopic vision

Question 6

What is the combination of the 2 vision?

Answer 6

mesotopic vision

Question 7

What is the refractive index?

Answer 7

Measure of the speed of light within a substance

Question 8

Innervation of lateral rectus

Answer 8

CN VI

Question 9

Innervation of superior oblique

Answer 9

CN IV

Question 10

Innervation of most of the extraocular muscles

Answer 10

CN III

Question 11

Refractive power of the cornea

Answer 11

48D

Question 12

refractive power of the lens

Answer 12

20-30D

Question 13

Mechanism of distant vision (4 steps)

Answer 13

1. Ciliary muscle relaxes
2. Zonula tenses
3. Lens flattens
4. Increase focal length, increase D

Question 14

Accomodation triad for near vision

Answer 14

1. Lens accommodation
2. Convergence of the eyes
3. Miosis (pupils constrict)

Question 15

Efferentation of accommodation through EW (4)

Answer 15

EW - ciliary ggl - PARAS - ciliaris, papillary sphincter

Question 16

Efferentation of accommodation through oculomotor nucleus

Answer 16

directly to extraocular muscles (except LR and SO)

Question 17

What is normal vision called?

Answer 17

Emmetropia

Question 18

What is farsightedness called?

Answer 18

Hyperopia / hypermetropia

Question 19

What is presbyopia?

Answer 19

farsightedness due to loss of elasticity

Question 20

What produces aqueous humor?

Answer 20

ciliary processes

Question 21

Resorbtion of aqueous humor?

Answer 21

Canal of schlemm

Question 22

Resorption of vitreous humor?

Answer 22

filtration at retinal vessels

Question 23

Roles of aqueous humor? (2)

Answer 23

• keeps anterior chambre pressurized

- maintenance of the eye’s shape

Question 24

Roles of vitreous humor? (2)

Answer 24

• Physical support for the retina

- Maintenance of the eye’s shape

Question 25

Which chart do we use to measure VisAc

Answer 25

Snellen chart

Question 26

5 types of neurons in the retina

Answer 26

• photoreceptors
• ganglion cells
• bipolar cells
• horizontal cells
• amacrine cells

Question 27

Which cells of the retina generate an AP for CN II?

Answer 27

ganglion cells (ONLY ONES!)

Question 28

Role of bipolar cells

Answer 28

connect photoreceptors and ganglion cells radially

Question 29

Role of horizontal cells

Answer 29

Interconnect photoreceptors and bipolar cells

Question 30

Role of amacrine cells

Answer 30

Interconnect bipolar cells and ganglion cells

Question 31

10 layers of the retina

Answer 31

1. Pigmented epithelium
2. Photoreceptor layer
3. Outer limiting membrane
4. Outer nuclear layer
5. Outer plexiform layer
6. Inner nuclear layer
7. Inner plexiform layer
8. Ganglion cells layer
9. Nerve fibre layer
10. inner limiting membrane

Question 32

What forms the limiting membrane?

Answer 32

The Müller cell

Question 33

Where are rods mostly located?

Answer 33

Densely at the periphery of the retina, except in fovea and optic disc

Question 34

Where is the density of cones highest?

Answer 34

At the fovea

Question 35

3 subtypes of cones

Answer 35

• blue (short, 419nm)
• green (medium, 533nm)
• red (long, 564nm)

Question 36

3 layers of the eye

Answer 36

• fibrous
• vascular
• retina