Brainscape's Knowledge GenomeTM

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


See full index

Ocular Anatomy > Lecture 9: Retina > Flashcards

Lecture 9: Retina Flashcards

1
Q

how many layers does the retina have?

A

10

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

what are 2 divisions of the retina

A

sensory and neural

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

what is the 10th outermost layer?

A

retinal pigment epithelium (RPE)

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

what are the 7 cells in the retina

A
  1. photoreceptors
  2. horizontal cells
  3. bipolar cells
  4. amacrine cells
  5. interplexiform cells
  6. ganglion cells
  7. Müller cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the 10 layers of the retina?

A
  1. Internal limiting membrane (ILM)
  2. Nerve fiber layer (NFL)
  3. Ganglion cell layer (GCL)
  4. Inner plexiform layer (IPL)
  5. Inner nuclear layer (INL)
  6. Outer plexiform layer (OPL)
  7. Outer nuclear layer (ONL)
  8. External limiting membrane (ELM)
  9. Photoreceptor layer (PR)
  10. Retinal Pigmented epithelium (RPE)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the 5 RPE functions?

A
  1. Absorption of stray light
  2. Protection against toxic and oxidative damage
  3. Formation of blood-retina-barrier
  4. Selective transport of substances to and from the retina
  5. Elimination of metabolic waste
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Monolayer of polarized cuboidal cells separate what?

A

photoreceptors from their underlying blood supply (choroid)

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

The PR layers contain what?

A

the outermost portion of photoreceptors, the portion containing the photopigment.

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

PRS are specialized cells that do what?

A

convert light energy into a neural message (phototransduction).

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

The outer portions of the PRs are adapted for what?

A

capturing light, while their inner parts are for transmitting the signal.

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

what are two types of PRs?

A

rods and cones

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

what are 7 parts common to PRs

A
  1. Synaptic terminal
  2. Inner Fiber
  3. Cell body
  4. Outer Fiber
  5. Inner Segment (IS)
  6. Cilium (Connecting Stalk)
  7. Outer Segment (OS)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Outer Segment (OS)

A

Stack of membranous discs with photopigment in the membrane of the discs and plasma membrane of the cell.

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

what are the areas called inside and outside discs?

A

The area inside of the disc is called the intradiscal space, the area between the disc is the extra disc space

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

what structures are at the apical end of the RPE and project between the outer segments of the rods?

A

microvilli

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

Cilium (connecting stalk)

A

Act to move OS towards direct path of light

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

inner segment consists of what?

A

– ellipsoid region (mitochondria) near the cilium

– myoid region (endoplasmic reticulum & golgi apparatus) near outer fiber

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

The inner fiber is the what of the photoreceptor.

A

axon

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

the axon extends from where and forms what?

A

Extends from cell body and forms specialized ending, the synaptic terminal

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

how many rods are there?

A

92-120 million rods

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

are rods specialized for light or dark?

A

dark: Dim light vision (scotopic)

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

where is rhodopsin located?

A

disc membrane

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

where is rod peak density?

A

in a ring 4.5 mm

outside the fovea

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

T/F: THERE ARE NO RODS IN THE FOVEA

A

T

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

rod outer segment contains how many discs?

A

600-1000 discs

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

Each disc membrane is separate

from the plasma membrane, except where?

A

at the base where the intradisc space is continuous with the extracellular space

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

how many cones are there?

A

5-6 million cones

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

are cones specialized for light or dark?

A

light: Bright illumination (photopic) and color

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

the disc membrane contains what and are sensitive to what?

A

Contain 1 of 3 photo pigments (conopsins)

stored in the disc membrane that are sensitive to different wavelengths of light

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

T/F: Cone OS is longer and more stout than those of rods

A

F: Cone OS is shorter and more stout than those of rods

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

Cones discs are shed at end of day and are phagocytosed by what?

A

RPE

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

OS of cones are enclosed by and continuous with?

A

Outer segment of cones is enclosed by Plasmalemma as in Rods but it is continuous with membrane forming most discs.

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

PR Synaptic Terminals: Rods inner fibers give way to what?

A

Inner fibers give way to a spherule (synapses with rod bipolar cell & process of horizontal cell)

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

PR Synaptic Terminals: Cones inner fibers give way to what?

A

Inner fibers give way to pedicle (synapses with several interneurons)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

when are rod discs shed?

A

in the early morning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

when are cone discs shed?

A

during the evening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

discs are phagocytosed by?

A

RPE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

The external limiting membrane lies next to what?

A

the outer edge of the outer nuclear layer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

zonula adherens are between what two cells?

A

PRs and Muller Cells

40
Q

the external limiting membrane acts as a barrier to what?

A

the passage of large molecules

41
Q

rods and cone cell bodies are contained where

A

the external limiting membrane

42
Q

cone cell bodies lie in a single layer close to what?

A

external limiting membrane

43
Q

Cell bodies of Rods are arranged how?

A

in several rows inner to cone cell body

44
Q

ONL is thickest in the Fovea - how many layers of cone nuclei

A

10

45
Q

The outer plexiform layer (OPL) can be thought of as having 2 layers:

A
  1. a wide outer band

2. thinner inner band

46
Q

A wide outer band composed of

A

the inner fibers (aka Henle’s fibers) of the rods and cones

47
Q

A thinner inner band made up of

A

the synaptic terminals of photoreceptors, dendrites of bipolar cells, as well as horizontal cell axons and dendrites

48
Q

where do the synaptic terminals synapse with the dendrites of bipolar and horizontal cells

A

Outer plexiform layer

49
Q

The outer plexiform layer is where the photoreceptor cells make their synaptic connections

A

bipolar cells

50
Q

The inner retina is supplied by

A

Retinal vasculature

51
Q

the outer retina is supplied by

A

choroid

52
Q

what layer marks the deepest penetration of blood vessels from the central retinal vasculature

A

inner nuclear layer

53
Q

The inner nuclear layer contains nuclei of 5 basic types of neural cells - what are they?

A
  1. amacrine cells
  2. horizontal cells
  3. bipolar cells
  4. muller cells
  5. interplexiform cells
54
Q

amacrine cells:

A

intermediate synaptic connections between the bipolar and ganglion cells (transfer signal parallel).

55
Q

horizontal cells:

A

intermediate synaptic connection between bipolar and photoreceptor cells.

56
Q

Bipolar cells:

A

Dendrites synapses with PR and horizontal cells, Axon synapses with ganglion and amacrine cells

57
Q

Muller cells:

A

extends throughout retinal layers, supportive role and structure.

58
Q

Interplexiform cells:

A

synapse to Amacrine cells and bipolar cells, provide feedback from inner to outer layers of retina

59
Q

what layer is composed of the dendrites of the retinal ganglion cells and the axons of bipolar cells

A

the inner plexiform layer

60
Q

The inner plexiform layer is where the bipolar cells make their synaptic connections with

A

ganglion cells

61
Q

This layer is generally one cell thick, but near the macula the layers pile up.

A

Ganglion Cell Layer

62
Q

Retinal Ganglion cells are the output cells of the retina that communicate with

A

the central visual system structures.

63
Q

The retinal ganglion cells are the primary cells affected in

A

glaucoma

64
Q

The ganglion cells layer contains the cell bodies of

A

ganglion cells

65
Q

The nerve fiber layer is made up of

A

unmyelinated fibers (do not aquire myelination until the axons pass through the lamina cribrosa)

66
Q

does the nerve fiber layer increase or decrease one moves towards the optic nerve head

A

increase

67
Q

in the NFL all fibers exit where?

A

All the fibers exit at the optic disc, thus it is thicker there.

68
Q

The central retinal vessels are located primarily in

A

NFL/GCL

69
Q

The ganglion cell to photoreceptor in the macular region is almost

A

1:1

70
Q

T/F: Moving outward from the macular the ratio changes with one ganglion cell representing input from many photoreceptors.

A

T

71
Q

what layer is the most vitread of all the retinal layers?

A

internal limiting membrane

72
Q

internal limiting membrane is formed by

A

footplates of Muller cells, which are covered by a basement membrane.

73
Q

Anteriorly, the ILM of the retina is continuous with

A

the ILM of the covering the ciliary body

74
Q

posteriorly, at the optic disc, footplates of Muller cells are replaced by

A

astrocytes that form the ILM of the optic disc.

75
Q

Müller cells are long glial cells that extend

A

from the ILM to just below the ELM

76
Q

Müller cells provide what

A

support and maintain extracellular environment

77
Q

Central retina is designed for

A

high visual acuity

78
Q

the central retina has certain what

A

structural modifications from the peripheral retina

79
Q

the central retina contains

A
  1. Macula
  2. Fovea
  3. Foveola
80
Q

how big is the macula?

A

Macula is 5.5 mm diameter

81
Q

how big is the center of the macula and where is it located?

A

Its center is 3.5 mm lateral to the temporal edge of the optic disc and 1 mm below the center of the disc

82
Q

why does the macula appear dark?

A

Appears dark due to the change in RPE morphology (taller and contain more pigment)

83
Q

why is yellow hue often observed due to

A

increased amounts of Xanthophyll (lutein and zexanthin) in the ganglion and bipolar cells: Antioxidant, UV protection

84
Q

what is a distinguishing feature of the macula

A

presence of an intraretinal pigment – xanthophyll

85
Q

what portion of the retina provides the best visual acuity

A

fovea

86
Q

are rods or cones found in the fovea

A

only cones

87
Q

how big is the fovea?

A

1.5 mm diameter

88
Q

clivus:

A

Walls slope downward toward the foveola

89
Q

is the fovea vascular or avascular

A

avascular

90
Q

what layers are present in the fovea

A

Only outer retinal layers are present

91
Q

The OS of the cones are elongated for

A

maximizing packing density (150,000 - 300,000 cone cells/mm2)

92
Q

The inner fibers of photoreceptors found in the outer plexiform layer are horizontally or vertically
oriented

A

horizontally oriented (vertical elsewhere in the retina).

93
Q

the horizontally orientated layer is referred to as

A

Nerve Fiber Layer of Henle

94
Q

The layers of the fovea are dependent upon

A

the underlying RPE and choriocapillaries for their metabolic support

95
Q

foveola

A

Center of the fovea

96
Q

how big is the foveola

A

.35 mm in diameter

97
Q

what is present in the foveola

A
  • Cone concentration is highest here
  • Only outer retinal layers present
  • Foveal reflex

Ocular Anatomy (15 decks)

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