Retinal Topography And Vasculature

Question 1

What is the retinas job

Answer 1

Innermost part of eye that does transduction and sends signal to brain

Question 2

What is the retina the window into

Answer 2

The CNS and cardiovascular system

Question 3

What happens in the retina

Answer 3

• light energy is transformed into a neural signal (phototransduction)
• signal is modified within the retina
• contains the first three cells of the visual pathway: photoreceptors (1st), bipolar cells (2nd), and ganglion cells (3rd)
• interneurons
• neuroglia cells

Question 4

What must happen for light to reach the 1st order neuron

Answer 4

Light must pass through all layers of the retina to reach the 1st order neuron wher it is converted into neural signal by the process of phototransduction. The signal is modified by the 2nd and 3rd order neurons and sent to the brain

Question 5

How many layers of the retina

Answer 5

10

Question 6

What are the inner 9 layers collectively referred to as

Answer 6

The sensory or neural retina

Question 7

What is the 10th retinal layer

Answer 7

RPE

Question 8

What are some cell types located within the retina

Answer 8

Many

-photoreceptors, horizontal cells, bipolar cells, amacrine cells, interplexiform cells, ganglion cells, and muller cells

Question 9

Are all regions of the retina the same

Answer 9

No

Question 10

What are the outer layers of the retina

Answer 10

Photoreceptor layer
External limiting membrane
Outer nuclear layer
Outer plexiform layer

All dealing with the photoreceptors

Question 11

What is in the photoreceptor layer

Answer 11

• rod outer segment
• rod inner segment
• cone outer segment
• cone inner segment

Question 12

What is within the outer nuclear layer

Answer 12

Row of cone nuclei

Multiple rows of rod nuclei

Question 13

What is within the outer plexiform layer

Answer 13

Contains rod spherules and cone pedicles

Question 14

What do photoreceptors span

Answer 14

Outer retina (photoreceptor layer, external liming membrane, outer nuclear layer, and outer plexiform layer)

Question 15

Role of photoreceptors

Answer 15

Absorb light photons and convert them into an electrochemical event (nerve signal) through the process of phototransduction.

Rods and cones

Question 16

How many cones

Answer 16

5-6mill

Question 17

What percentage of cones are in the fovea

Answer 17

10%

Question 18

What do cones detect

Answer 18

Bright illumination (photopic) and color

Question 19

What are the 3 types of cones

Answer 19

S cones (blue, 420)
M cones (green 531)
L cones (red 588)

Question 20

What is the only photoreceptor in the fovea

Answer 20

Cones

Question 21

What type of cone is NOT in the center of the fovea

Answer 21

S cones

Question 22

How many rods

Answer 22

92-120 mill

Question 23

What do rods detect

Answer 23

Dim vision (scotopic)

Question 24

What do rods contain

Answer 24

Photopgiment, rhodopsin, which is located in the disc membrane

Question 25

Peak density of rods

Answer 25

In a ring 4.5mm outside the fovea

Question 26

Are there rods in the fovea

Answer 26

No

Question 27

Blind spot

Answer 27

ONH Nasal 20 degrees

Question 28

Horizontal cells

Answer 28

Lateral processes between the cells

Question 29

What is the second cell in the chain of phototransudction

Answer 29

Bipolar cells

Question 30

What do amacrine cells do

Answer 30

Processing

Question 31

What do muller cells do in the retina

Answer 31

They are the radial glial cells of the retina Maintain structural support/buffering environment

Question 32

Where are there astrocytes in the retina

Answer 32

RNFL around blood vessels

Question 33

What does glaucaom kill

Answer 33

``` Ganglion cells (3rd one) Stem cells wont work here ```

Question 34

Retinitis pigmentosa affects what

Answer 34

Photoreceptors | Stem cells could work here

Question 35

Retinal thickness

Answer 35

80 microns to 320

Question 36

Fovea retinal thickness

Answer 36

150-200

Question 37

What is the thinnest part of the retina

Answer 37

Ora serrata | 80 microns

Question 38

Where is the ora serrata more serrated

Answer 38

Nasally

Question 39

Where is the ora serrata more smooth

Answer 39

Temporally

Question 40

What is there a dense population of in the central retina

Answer 40

Cones

Question 41

What is the central retina designed for

Answer 41

Color vision and fine detail discrimination

Question 42

What is there a dense population of in the peripheral retina

Answer 42

Rods

Question 43

What is the peripheral retina designed for

Answer 43

Night vision and motion detection

Question 44

How big is macula

Answer 44

5.5mm to 6mm diamter

Question 45

What is the only area of the retina that contains more than 1 layer of retinal ganglion cells

Answer 45

Macula

Question 46

What is there high levels of in the macula

Answer 46

Carotenoids

Question 47

What are the names ofhte parts of the macula from inside out

Answer 47

``` Umbo Foveola Foveal avascular zone fovea Parafovea Perifovea Macula ```

Question 48

What causes the foveal light reflex

Answer 48

Umbo

Question 49

Central depression of macula that is 1.5mm in diamter

Answer 49

Fovea

Question 50

Walls of fovea

Answer 50

Walls slope giving rise to light reflex known as foveal light reflex

Question 51

What photoreceptors are in the fovea

Answer 51

Cones only

Question 52

How are the axons of cones oriented in the fovea

Answer 52

Obliquely in the outer plexiform layer of the fovea (henle fibers)

Question 53

How is the inner retinal layers displaced in the fovea

Answer 53

Laterally

Question 54

Central 350 microns of the fovea

Answer 54

Foveola

Question 55

Dense packing of cones makes them appear rod like in structure in this area

Answer 55

Foveola

Question 56

What is the thinnest region of the fovea

Answer 56

Foveola

Question 57

Cone inner fibers that are oriented obliquely within the fovea are called ________

Answer 57

Henle fibers Thus, the OPL in the fovea is often referred to as Henke's fiber layer

Question 58

What is Henles fiber layer

Answer 58

Outer plexiform layer obliquely displaced in the fovea

Question 59

Extend 0.5mm from the foveal rim

Answer 59

Parafovea

Question 60

Highes accumultion of bipolar and retinal ganglion cells

Answer 60

Parafovea

Question 61

Rod photoreceptors reach their peak density here

Answer 61

Parafovea

Question 62

1.5mm from the parafoveal rim

Answer 62

Perifovea

Question 63

Axons of Henles fiber layer resume their vertical orientation here

Answer 63

Perifovea

Question 64

Peripheral retina

Answer 64

Rod dominated region of central retina | Terminates at the ora serrata

Question 65

What is the peripheral termination of the retina

Answer 65

Ora serrata

Question 66

Outer Retinal vasculature

Answer 66

Choroid (for photoreceptors)

Question 67

Vasculature for the inner retina

Answer 67

Retinal vessels (central retinal vasculature)

Question 68

Is there an overlap between the choroidal blood supply and the central retina lblood supply

Answer 68

No

Question 69

Cilioretinal artery

Answer 69

20% of population has this. It is collateral blood supply to the macula

Question 70

Which is more nasal, central retinal artery or vein

Answer 70

Artery

Question 71

Which is more temporal, central retinal artery or vein

Answer 71

Vein

Question 72

Which is bigger, central retina artery, or vein

Answer 72

Vein | 2:3

Question 73

When does the central retinal artery loose its elastic tunic

Answer 73

Upon entering the eye | This distinguishes it from the muscular arteries in other parts of body

Question 74

What is the tunica elasticum of the central retinal artery replaced with when it enters the eye

Answer 74

Prominent tunica media composed of smooth muscle

Question 75

Control of retinal vasomotor tone is

Answer 75

Auto regulated

Question 76

Control of choroidal vasomotor tone is

Answer 76

Neuroregulated

Question 77

What does the smooth muscle in the tunica media respond to in the central retinal artery

Answer 77

IOP and systems pressure, and metabolic waste levels

Question 78

Pericytes in the retinal caps

Answer 78

Helps blood flow

Question 79

Pericytes in DM

Answer 79

Increased blood sugar converts glucose to OH which kills pericytes and weakens others, causing fluid to leak into the eye through there

Question 80

Loss of pericytes and endothelial cells from retinal caps in DM patients can lead to

Answer 80

Microaneurysms, hemorrhages, exudates, and fluid in the macular region

Question 81

What are the two layers of the retinal cap plexus

Answer 81

Deep cap plexus | Supercficial cap plexus

Question 82

Round hemorrhages

Answer 82

Deep

Question 83

Flame shaped hemorrhage

Answer 83

Superficial cap plexus | RNFL

Question 84

What kind of shift do you get with macular edema

Answer 84

Hyperopic shift

Question 85

Which branch is more likely to be occluded in bran retinal vein occlusion

Answer 85

Superior, just because there are more of them

Question 86

Neovascularization

Answer 86

Will be leaky. Any vessels developed after Birth will be leaky

Question 87

When is it a good time to have a cilioretinal artery

Answer 87

Central retinal artery occlusion