Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ocular Block 7 > Retinal Development > Flashcards

Retinal Development Flashcards

1
Q

Where do the neural folds and the neural groove originate

A

On the embryonic disc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens to the neural folds and the neural groove to form a neural tube

A

They get “zipped” up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 germ layers

A

Ectoderm
Mesoderm
Endoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What kind of structures are the neural crest cells going to be

A

PNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What kind of structures are the neural tube going to become

A

CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Are CN CNS or PNS?

A

All are peripheral except CN2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the out pouches of the optic pit

A

Optic vesicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is it called when the neural tube closes

A

The embryo is in a tube within a tube concept at this point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the inner tube of the tube within the tube concept

A

Neural tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the outer tube of the tube within the tube concept

A

Surface ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What lies between the inner and outer tube in the tube within a tube concept

A

Mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the two evaginations will form off the cranial portion of the neural tube

A

Optic vesicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the optic vesicles made up of

A

Neural ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Formation of the optic cup

A

The optic vesicle will elongate forming the optic stalk. The end of the stalk will come in close proximity to the outer tube (surface ectoderm)
When the optic vesicle encoutners the surface ectoderm, it will being to fold inward and invaginate.
This infolding will create the optic cup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does the apex to apex formation occur

A

As the optic cup folds upon itself, the back of the cup comes into contact with the layer from the front of the cup.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The small space left over by the apex to apex folding is initially called the _______

A

Intraretinal space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What eventually happens to the intranet in all space

A

Eventually just becomes a potential space as the layers connect together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the apex to apex cells in the most posterior part of the optic cup

A

Outer layer is the RPE

Inner layer i the neural retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the apex to apex cells in the more anterior part of the optic cup going to become

A

Outer layer is the PCE

Inner layer is the NPCE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the cells that are apex to apex that are most anteriorly in the optic cup

A

Outer layer is the anterior iris epithelium

Posterior iris epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How many layers are in the RPE

A

1 cell layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is essential for development of the RPE

A

Apposition of the two layers of the optic cup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the first retinal layer to differentiate

A

RPE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What event forms the RPE

A

Induction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the earliest pigmentation evident in the embryo

A

RPE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

When does the RPE become pigmented

A

1 month

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Base of each RPE cell

A

Is external toward the developing choroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Apex of each RPE cell

A

Internal toward the inner layer if the optic cup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

When do the cells of the inner layer of the optic cup proliferate and two zones are evident

A

Between weeks 4 to 6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

When does the neural retina subdivide into two distinct areas

A

Beginning around weeks 4 to 6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the 2 subdivisions of the neural retina at weeks 4 to 6

A

Outer area: germinating zone (thicker)

Inner area: marginal zone (thinner area)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Other than the neural retina deividing into two subdivisions, what else happens at weeks 4 to 6

A

A basal lamina is formed that will eventually become the inner limiting membrane of the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What happens at week 7

A

All migration occurs, forming the inner and outer neuroblastic layers, between which lies the transient fiber layer of Chievitz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

When do the formation of the inner and outer neuroblastic layers (separated by the transient layer of Chievitz) occur

A

Week 7

35
Q

What is a nucleus free zone that lies between the inner and outer neuroblastic layers

A

Transient fiber layer of Chievitz

36
Q

The formation of the two neuroblastic layers is complete during the _____ month

A

3rd

37
Q

Where does differentiation of the neural retinal cells begin first

A

In the central retina first and proceeds to the periphery

38
Q

What develops first, the central or peripheral retina

A

Central

39
Q

Layer development of the inner neuroblastic layer

A
  1. The ganglion cells migrate, forming a layer close to the basement membrane, and almost immediately send out their axonal processes, which become evident by week 8
  2. Biomolecular agents guide axonal growth towards termination in the LGN
  3. Muller cells located rather centrally in the inner neuroblastic layer develop at the same time. The bodies of the muller and amacrine cells remain in the inner neuroblastic layer but move slightly scleral
40
Q

How do ganglion cells move

A

Inward

41
Q

How do the muller and amacrine cells shift

A

Outward

42
Q

How do bipolar cells migrate

A

From the outer neuroblastic layer and settle near the muller and amacrine cells and the horizontal cell follows

43
Q

When is the fiber layer of Chievitz obliterated

A

When the bipolar cells migrate along with the horizontal cells

44
Q

When the bipolar and horizontal cells migrate and the fiber layer of Chievitz all move/ obliterate, what happens to the photoreceptor cells

A

They remain in the outer neuroblastic layer

45
Q

What happens in week 12

A

The photoreceptors are aligned along the outer side of the inner layer of the optic cup and adhering junctions appear between them

46
Q

When are the photoreceptors aligned along the outer side of the inner layer of the optic cup and adhering junctions appear between them

A

Week 12

47
Q

How are the photoreceptors aligned at week 12

A

Along the outer side of the inner layer of the optic cup with adhering junctions between them

48
Q

What forms the precursor of the external limiting membrane

A

Adhering junctions appearing between the photoreceptors aligned along the outer side of the inner layer of the optic cup

49
Q

What are the last cells of the neural retina to differentiate

A

Photoreceptor cells

50
Q

When do the photoreceptors differentiate

A

Month 5

51
Q

What photoreceptors differentiates first

A

Cones

52
Q

When do rods being to diffentiate

A

7th month

53
Q

Which develops first, inner segment of the photoreceptor or the outer segment of the photorecetor

A

Inner segment develops first

54
Q

What cells are initially all in the outer retina

A

Bipolar, horizontal, and PR

After migration, only the PR remain

55
Q

Where are the horizontal, amacrine, and muller cells developing

A

In the inner nuclear layer

56
Q

What is happening in the inner and outer plexiform layer

A

Filling with neuronal processes

57
Q

What forms the primitive internal limiting membrane

A

The fibers of the muller cells appear and extend to the basal lamina, forming the primitive internal limiting membrnae

58
Q

What does the muller cell provide

A

A scaffolding for cell development and appears to be involved with guiding the direction of axonal fiber growth

59
Q

What begins to appear at the same time as the plexiform layers?

A

Synaptic complexes

60
Q

What plexiform layer develops first

A

Inner plexiform

61
Q

Do cone pedicles or rod spherules develop first

A

Cone spherules

62
Q

What is established even before the outer segments of photoreceptors are completed

A

Photoreceptor synapses with bipolar cells

63
Q

When is the ganglion cell layer well established

A

Month 5

64
Q

What is one of the first layers to be well established

A

Ganglion cell layer

65
Q

Describe the horizontal raphe

A

Because the retinal development is more advances centrally than peripherally, the ganglion axons from the periphery must take an arched route above and below the macular area to reach the nerve head. The line of deviation at the horizontal temporal meridian is termed the horizontal raphe

66
Q

When does apoptosis of retina cells happen

A

5th month

67
Q

Retinal growth after month 6

A

No further mitosis, retinal growth continues because of cell differentiation, growth, and maturation

68
Q

When do cones begin to differentiate and accumulation of nuclei in the macula happen

A

Sixth month

69
Q

How many rows of ganglion cells are present

A

Up to 9

70
Q

What are the three stages of foveal displacement

A
  1. Displacement of inner retinal components to form the depression
  2. Migration of photoreceptors toward the center, which increases cone packing
  3. Maturation of the photoreceptors
71
Q

Ganglion cells and the cells of the inner nuclear layer in the seventh month

A

Begin to move to the periphery of the macula

72
Q

Fovea after birth

A
  • Still a single layer of ganglion cells and a thin inner nuclear layer across the no-depressed foveal area
  • by 4 months postpartum both these layers are displaced to the sloping walls of the fovea, leaving the cones of the outer nuclear layer as the only neural cell bodies in the center of the depression
73
Q

How long does the foveal depression continue to deepen after birth

A

Until about age 15 months

74
Q

What is the last the reach maturity in the developing eye

A

The foveola

75
Q

What is different about the cone inner fibers in the fovea

A

Elongate and adopt an oblique orientation (forming Henles fiber layer) in order to synapse with the cells of the inner nuclear layer, which have been displaced to the sloping walls

76
Q

VA of infants under one month

A

20/800 to 20/200

77
Q

VA of infants 2 months

A

20/150

78
Q

VA of infants 4 months old

A

20/60

79
Q

VA of infants 6 months old

A

20/20

80
Q

What cells start in the inner neuroblastic layer

A

Ganglion
Amacrine
Muller

81
Q

What cells being in the outer neurblastic layer

A

Bipolar
Horizontal
Photoreceptor

82
Q

Where does the ganglion end up

A

RNFL

GCL

83
Q

What cells end up in ther inner nuclear layer

A

Amacrine
Muller
Bipolar
Horizontal

84
Q

What layers do the photoreceptors end up occupying

A

Outer nuclear layer

Photoreceptor layer

Ocular Block 7 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions