Visual System - Anatomy

Question 1

Label an image of an eye.

Answer 1

Must include: pupil, iris, sclera, medial/lateral canthus, caruncle, limbus, eyelids, palpebral fissure,

Question 2

List types of tears.

Answer 2

basal
reflex
emotional

Question 3

Describe afferent innervation to the lacrimal system.

Answer 3

cornea, cranial nerve V1 – ophthalmic trigeminal

Question 4

Describe efferent innervation to the lacrimal system.

Answer 4

parasympathetic

Question 5

What neurotransmitter involved in the lacrimal system?

Answer 5

acetylcholine

Question 6

Where are tears produced?

Answer 6

lacrimal gland

Question 7

Tears drain through what?

Answer 7

two puncta, openings on medial lid margin

Question 8

Tears flow through (?) to gather in the (?).

Answer 8

superior/inferior canaliculi

tear sac

Question 9

From the tear sac, tears exit through (?) into (?).

Answer 9

tear duct

nasal cavity

Question 10

Function of the tear film?

Answer 10

Maintains smooth cornea-air surface
Oxygen supply to Cornea (no blood vessels)
debris removal
bactericide

Question 11

The tear film is composed of how many layers? Name them from superficial to deep.

Answer 11

superficial lipid layer
aqueous tear film
mucinous layer

Question 12

Superficial lipid layer is produced by?

Answer 12

Meibomian glands along lid margins

Question 13

What is the conjuctiva?

Answer 13

Thin, transparent tissue that covers the outer surface of the eye

Question 14

What does the conjuctiva cover?

Answer 14

It begins at the outer edge of the cornea, covers the visible part of the eye, and lines the inside of the eyelids

Question 15

Is the conjuctiva vascularised?

Answer 15

yes

Question 16

List the layers of the coat of the eye from superficial to deep.

Answer 16

sclera
choroid
retina

Question 17

Describe the sclera.

Answer 17

hard & opaque
protective outer layer
high water content

Question 18

Describe the choroid.

Answer 18

pigmented

vascular

Question 19

Describe the retina.

Answer 19

neurosensory tissue

Question 20

What is the cornea?

Answer 20

transparent, dome shaped window covering the front of the eye, low water content

Question 21

What is the cornea’s function?

Answer 21

refracting surface

2/3 of eye’s focusing power

Question 22

What are the 5 layers of the cornea?

Answer 22

epithelium
Bowman's membrane
stroma
Descemet's membrane
endothelium

Question 23

Function of endothelium of cornea

Answer 23

pumps fluid out of corneal and prevents corneal oedema

Question 24

What is uvea?

Answer 24

Vascular coat of eyeball and lies between the sclera and retina

Question 25

The uvea is composed of?

Answer 25

iris ciliary body choroid

Question 26

What is the purpose of the iris?

Answer 26

controls light levels inside the eye similar to aperture on a camera

Question 27

Opening of the iris is the?

Answer 27

pupil

Question 28

Structure of the lens?

Answer 28

Outer acellular capsule | Regular inner elongated cell fibres – transparency

Question 29

When the lens loses transparency with age, it's called?

Answer 29

cataracts

Question 30

List functions of the lens.

Answer 30

``` Transparency Regular structure Refractive Power 1/3 of the eye focusing power - higher refractive index than aqueous fluid and vitreous Accommodation Elasticity ```

Question 31

What is the retina responsible for?

Answer 31

capturing the light rays that enter the eye

Question 32

Light impulses are sent to the brain from the retina via?

Answer 32

optic nerve

Question 33

Where does the optic nerve reach the retina?

Answer 33

back of the eye near the macula, visible portion called optic disc

Question 34

Where is the macula located?

Answer 34

roughly in the centre of the retina

Question 35

What is the macula responsible for?

Answer 35

detailed central vision

Question 36

What is the fovea?

Answer 36

centre of the macula

Question 37

What are the concentration of rods and cones in the fovea?

Answer 37

highest conc of cones | lowest conc of rods

Question 38

Describe central vision. How is it assessed?

Answer 38

Detail day vision, colour vision Reading, facial recognition Loss of foveal vision – Poor visual acuity

Question 39

How is central vision assessed?

Answer 39

Assessed by visual acuity assessment

Question 40

Describe peripheral vision.

Answer 40

Shape, movement, night Vision Navigation vision Extensive loss of visual field – unable to navigate in environment, patient may need white stick even with perfect visual acuity

Question 41

How is peripheral vision assessed?

Answer 41

Assessed by visual field assessment

Question 42

Describe the layers of the retina.

Answer 42

outer middle inner

Question 43

Outer layer of the retina

Answer 43

photoreceptors | detection of light

Question 44

Middle layer of the retina

Answer 44

bipolar cells | local signal processing (improves contrast sensitivity, regulate sensitivity)

Question 45

Inner layer of the retina

Answer 45

retinal ganglion cells | transmission of signal from the eye to the brain

Question 46

What are the two classes of photoreceptors?

Answer 46

rods | cones

Question 47

Rods

Answer 47

longer outer segment with photo-sensitive pigment 100 times more sensitive to light than cones Slow response to light Responsible for night vision (Scotopic Vision) 120 million rods

Question 48

Cones

Answer 48

Less sensitive to light, but faster response Responsible for day light fine vision and colour vision (Photopic Vision) 6 million cones

Question 49

S cones capture what colour?

Answer 49

blue

Question 50

M cones capture what colour?

Answer 50

green

Question 51

L cones capture what colour?

Answer 51

red

Question 52

What is deuteranomaly/Daltonism?

Answer 52

most frequent form of colour blindness

Question 53

Which colour are people with deuteranomaly unable to perceive?

Answer 53

red

Question 54

What is the term used to describe full colour blindness?

Answer 54

achromatopsia