Lecture 1/5

Question 1

list the 3 types of supportive cells of the retina

Answer 1

1. mueller cells
2. macroglia
3. microglia

Question 2

what are the fibular baskets of the mueller cells ?

Answer 2

they are extensions that go into receptive layer

Question 3

describe the makeup of the ELM

Answer 3

it is a fusion of the cell walls in exact line of Mueller cells, cones, and rods

Question 4

describe the makeup of the ILM

Answer 4

it is a fusion of the footplates of the Mueller cells

Question 5

what is the largest cell in the retina?

Answer 5

Mueller cell

Question 6

astrocytes are a type of

Answer 6

macroglia

Question 7

astrocytes are associated with:

Answer 7

blood vessels and neurons

Question 8

where are astrocytes found?

Answer 8

from the nerve fiber layer to the inner nuclear layer

Question 9

what microglial cell is found in the retina?

Answer 9

wandering phagocytic cells

Question 10

where are microglia found?

Answer 10

from nerve fiber layer to outer plexiform layer

Question 11

the blood supply to the retina is from capillaries from what 2 places?

Answer 11

• central retinal artery (CRA)

- choriocapillaris

Question 12

capillaries from the central retinal artery (CRA) supply what part of the retina?

Answer 12

• from nerve fiber layer to outer edge of inner nuclear layer
• inner half of the retina (primary and secondary neurons)

Question 13

capillaries from the choriocapillaris supply what part of the retina?

Answer 13

outer half of the retina (rods and cones)

Question 14

what locations are there tighter attachments at the retina?

Answer 14

• anterior at the ora serrata
• posterior at the optic nerve
• a small but weaker attachment at the macula

Question 15

what causes the yellow color of the macula lutea?

Answer 15

a pigment called xenophyll

Question 16

what is the diameter of the macula lutea?

Answer 16

5.5 mm diameter

Question 17

the macula is relatively avascular. in what area is there no vessels?

Answer 17

the central 0.4 mm has no vessels

Question 18

what is the diameter of the fovea centralis (central part of macula)?

Answer 18

1.5 mm in diameter

Question 19

what is the floor of the fovea called and what does it not contain?

Answer 19

the foveola

-no blood vessels, no rods, no cones

Question 20

the diameter of the foveola is

Answer 20

0.35 mm diameter

Question 21

what is the very center of the foveola called?

Answer 21

the umbo (navel)

Question 22

what are the sloping walls of the fovea called?

Answer 22

clivus

Question 23

what is the inner ring of the fovea called and how wide is it?

Answer 23

inner ring: parafovea

0.5 mm wide

Question 24

what is the outer ring of the fovea called and how wide is it?

Answer 24

outer ring: perifovea

1.5 mm wide

Question 25

what retinal layers are present at the foveola?

Answer 25

layers 1-5 and the ILM

Question 26

what retinal layers are NOT present at the foveola?

Answer 26

layers 6, 7, 8, and 9

Question 27

what is the layer called where the fibers are pushed and going horizontally instead of vertically?

Answer 27

fiber layer of Henley

Question 28

what is the diameter of the optic nerve head?

Answer 28

1.5 mm

Question 29

what is the excavation of the optic nerve head called and why is it important?

Answer 29

called the cup, a result of embryological development, important for C/D ratio and glaucoma diagnosis

Question 30

what is unique about the ILM and the optic nerve head?

Answer 30

the ILM does not go over the optic nerve, instead there is a thin layer of astrocytes

Question 31

what is the layer of astrocytes over the optic nerve called?

Answer 31

central meniscus of Kuhnt

Question 32

what is the lamina cribrosa?

Answer 32

the bridges across the posterior scleral foramen

Question 33

what is the purpose of the lamina cribrosa?

Answer 33

to allow the axons of the ganglion cells to exit out of the eye with perforations and holes for the axons

Question 34

what is the anterior portion of the lamina cribrosa derived from?

Answer 34

derived from the choroid | -made up of astrocytes and elastic tissue

Question 35

what is the posterior portion of the lamina cribrosa derived from?

Answer 35

derived from the sclera | -made up of collagen fibers and some astrocytes

Question 36

where does myelination of the fibers occur?

Answer 36

at the lamina cribrosa

Question 37

where is the thickest area of the retina?

Answer 37

optic nerve head | 560 microns thick

Question 38

where is the thinnest area of the retina?

Answer 38

ora serrata | 100 microns thick

Question 39

how thick is the foveola?

Answer 39

130 microns thick

Question 40

what is the average thickness throughout the retina?

Answer 40

370 microns

Question 41

what are the nerve fibers that travel from the macula called?

Answer 41

papillomacular bundle

Question 42

what are the nerve fibers that travel from the superior/ inferior temporal retina called?

Answer 42

arcuate fibers

Question 43

what are the nerve fibers that travel from the superior/ inferior nasal retina called?

Answer 43

radial fibers

Question 44

what is the superior inferior demarcation line called?

Answer 44

horizontal raphe

Question 45

how many axons does the optic nerve contain?

Answer 45

1.2 million axons

Question 46

what is the extent of the optic nerve?

Answer 46

from the globe in the back of the eye to the optic chiasm

Question 47

what is the length of the optic nerve?

Answer 47

500 mm long

Question 48

diameter of the optic nerve

Answer 48

3-4 mm

Question 49

what are the 3 meninges surrounding the optic nerve?

Answer 49

dura mater, arachnoid, pia matter

Question 50

what is important about the subarachnoid space?

Answer 50

it contains the cerebrospinal fluid (CSF)

Question 51

how would a space occupying lesion in the brain manifest ocularly?

Answer 51

a tumor, for example, could cause pressure in the CSF that is transmitted up the back of the eye and causes swelling of the optic nerve

Question 52

what is the optic chiasm?

Answer 52

the crossing of the optic nerves (decussation)

Question 53

how many of the optic nerve fibers will cross at the optic chiasm?

Answer 53

1.4 million fibers

Question 54

what is the optic tract?

Answer 54

from the optic chiasm to the lateral geniculate body (LGB)

Question 55

what is special about the LGB

Answer 55

it is the first synapse of the axons from the ganglion cell