Brainscape's Knowledge GenomeTM

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


See full index

Anatomy and Physio Final > RPE > Flashcards

RPE Flashcards

1
Q

How is the RPE and photoreceptor outer segment aligned?

A

apex to apex

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

What is in the neural retina?

A

photoreceptors, bipolar, ganglion, horizontal and amacrine cells

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

Where is the ocular ventricle?

A

The potential space between the RPE and POS

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

After lens induction begins, the _____ _____ collapses back onto itself. The inner invagination becomes the _______ while the outer part becomes the _______

A

After lens induction begins, the optic vesicle collapses back onto itself. The inner invagination becomes the neural retina while the outer part becomes the RPE

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

The basement membrane of the RPE becomes ____ ____ during development. The basement of the neural retina becomes the ____ ____ ____

A

The basement membrane of the RPE becomes Bruch’s membrane during development. The basement of the neural retina becomes the inner limiting membrane

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

Where would you find microvilli on the RPE?

A

the apical portion. Microvilli envelope the photoreceptors

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

The epithelial cells of the Blood Retinal barrier are bound together by _____ _____ and divide the cells into apical halves that face the _______ and basal halves that face the ______

A

The epithelial cells of the Blood Retinal barrier are bound together by tight junctions and divide the cells into apical halves that face the receptors and basal halves that face the choroid

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

What gives the RPE its black appearance?

A

Pigment granules

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

What is proliferative vitreoretinopathy?

A

Pigment granules separate from the RPE as free cells and appear as “tobacco dust” in the vitreous. Cells then settle and form contractile fibrocellular membranes

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

What part of the retina uses the most energy?

A

The outer segments

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

Photoreceptor survival depends on having _____ and _____ in large quantities

A

blood and glucose

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

What are the four extreme properties that the choroid has developed to meet the demands of the photoreceptors?

A
  1. High permeability
  2. High throughput of blood - more blood faster
  3. High oxygen levels
  4. No auto-regulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Name the two problems created by the thin and sparse central retinal circulation (made necessary since it lies in the path of light)

A
  1. Very little oxygen reserve

2. Small vessel diameter

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

What are the five functions of the RPE? (RPEAM)

A

Retinal barrier
Photoreceptor renewal and light absorption
Environment protection against superoxides
A… Vitamin A metabolism and storage
Matrix synthesis

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

What are the two aspects of the blood-retinal barrier?

A
  1. Tight junctions of the endothelial cells of the CRC

2. Tight junctions of the RPE keeping blood out of the retina

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

The fenestrated choriocapillaries permit leakage of _______

A

protein

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

Protein concentration in front of the RPE is ____ while the concentration in the ECS behind the RPE is ____

A

Protein concentration in front of the RPE is low while the concentration in the ECS behind the RPE is high

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

The RPE can absorb up to ___% of the aqueous secretion in a day

A

50%

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

What are the factors preventing RPE/retina detachment?

A
  1. Oncotic fluid gradient
  2. Finger-like folds of the RPE
  3. Interphotoreceptor matrix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Due to the high membrane fluidity required by the retina, the ____ bonds of the _____ _____ _____ make the retina highly susceptible to superoxide attack.

A

Due to the high membrane fluidity required by the retina, the double bonds of the unsaturated fatty acids make the retina highly susceptible to superoxide attack.

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

Hurler’s syndrome is the buildup of _____ molecules due to an improperly functioning degrading _____

A

Hurler’s syndrome is the buildup of GAG molecules due to an improperly functioning degrading enzyme

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

Photoreceptors are degraded by _____ and ____

A

Photoreceptors are degraded by phagocytosis and autophagy

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

A single RPE cells is responsible for phagocytosing ____ or more rods

A

10

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

Define autophagy

A

Self-digestion by a cell through the action of enzymes of the same cell

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

What are the two patterns of photoreceptor replacement?

A
  1. Membrane replacement

2. Molecular replacement

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

All structures in the rod turnover during membrane replacement except for ____

A

DNA

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

What two molecules are replaced independent of the discs in rods?

A

transducin and PDE

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

Where would the disc accumulate if photoreceptor renewal did not take place?

A

subretinal space

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

Phagocytosis of the photoreceptor outer segment is carried out by the ____

A

RPE

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

In order to digest the outer segment portion of a photoreceptor, a _____ fuses with the ____ ____.

A

In order to digest the outer segment portion of a photoreceptor, a lysosome fuses with the RPE phagosome

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

In embryogenesis up till 6 months, growth of photoreceptors is ______ than phagocytosis. From Age 6 months until adulthood, growth is ______ to phagocytosis. Disease is observed when growth is ______ than phagocytosis.

A

In embryogenesis up till 6 months, growth of photoreceptors is greater than phagocytosis. From Age 6 months until adulthood, growth is equal to phagocytosis. Disease is observed when growth is less than phagocytosis.

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

What can radioautography do?

A

Allows the researcher to follow the synthesis of a molecule by administrating a “pulse” of radiolabeled molecule into the molecule.

33
Q

A radiolabeled molecule is referred to as ____

A

“hot”

34
Q

An unlabeled molecule seen during radioautography is referred to as _____

A

“cold”

35
Q

Photoreceptor renewal is _______ in cones than in rods

A

Slower

36
Q

What do the proteins incisin and peripherin do in photoreceptors?

A

control the spacing of the discs

37
Q

Where are polysaccharides found in a photoreceptor?

A

Between the discs. Acts as a cushion

38
Q

The label in radioautography is found in a lipid-surrounded vesicle known as a _______

A

Schleppersome

39
Q

Rods are phagocytosed 1.5 hours after _____ and the cones are phaocytosed 1.5 hours after _____

A

Rods are phagocytosed 1.5 hours after dawn and the cones are phaocytosed 1.5 hours after nightfall

40
Q

The circadian rhythm runs on a ___ hour cycle

A

12

41
Q

True / False. Seeing and circadian control rely on the same receptor

A

Fuck no

42
Q

Constant light results in the ______ of the outer segments while constant darkness results in _____ of the outer segments

A

Constant light results in the shortening of the outer segments while constant darkness results in elongation of the outer segments

43
Q

What two methods has the cornea developed to act again oxidation by superoxides?

A

Chemical mechanism - superoxide dismutase

Anatomical mechanism - replacement of tissue

44
Q

Oxidation takes place across what type of bond?

A

double bonds

45
Q

Why can’t the lens replace its own tissue?

A

Cells are sloughed off towards the center

46
Q

Shorter wavelength light is ______ destructive than longer wavelength light

A

more

47
Q

Why is the retina the weakest tissue of the body?

A

Retina has highly fluid membranes

48
Q

Macular pigments surround the macula and absorb _____ light in order to fight off free radicals.

A

blue light

49
Q

The lens protects the retina by absorbing most of the incoming _____ light

A

UV light

50
Q

Superoxides can be broken down to hydrogen peroxide and oxygen in the presence of ____, ____, ___, and _____ ______

A

Zn, Cu, Mn, and superoxide dismutase

51
Q

Hydrogen peroxide may revert back to superoxide in the presence of ____

A

Fe ions

52
Q

The Glutathione peroxidase pathway (the predominant retinal pathway) requires ____

A

Se++

53
Q

As lipids become crosslinked, the super destructive element ________ is kicked out

A

malonaldehyde

54
Q

Vitamins __ and __ are used to get rid of malonaldehyde

A

Vitamins C and E

55
Q

When lipofuscin accumulates in the RPE, it becomes _____

A

Drusen

56
Q

Early accumulation of lipfuscin is seen in _____ and _____

A

Stargardt’s and ARMD

57
Q

Each RPE cell ingests more than any other phagocytic cell at __% of its own volume

A

7%

58
Q

11-cis-retinal + aporhodopsin -> ____ + _____

A

Rhodopsin + water

59
Q

When exposed to light, rhodopsin breaks down into ______ + ______

A

aporhodopsin + all-trans-retinal

60
Q

Humans typically begin with _______ photoreceptors

A

100,000,000

61
Q

Retinal detachment = starvation due to a lack of ____ and ____

A

oxygen and glucose

62
Q

______ _____ is the basement membrane of the RPE

A

Bruch’s membrane

63
Q

What happens when Bruch’s membrane is stretched?

A

neovascularization

64
Q

Fatty acid deficiency in the choroid results in the inability to delivery ____ _ to the retina. This may lead to ____ ____

A

Vitamin A. Night blindness

65
Q

_____ ____ is a generice name for a group of inherited disorders that cause progressive loss of photoreceptor and RPE function

A

Retinitis Pigmentosa (RP)

66
Q

RP prevalence is about

A

1:4,000

67
Q

Damage to the ___ is predominant in RP

A

rods

68
Q

In the oxygen toxicity hypothesis: as the outer segments are lost, oxygen use by the ____ diminishes and the ___ ___ is flooded with oxygen.

A

In the oxygen toxicity hypothesis: as the outer segments are lost, oxygen use by the photoreceptors diminishes and the outer retina is flooded with oxygen.

69
Q

photoreceptors that survive oxygen toxicity are damaged and upregulate expression of _____ _____ which slows degeneration

A

protective factors

70
Q

What are the two types of ARMD?

A

dry and wet

71
Q

In Dry ARMD, drusen appears which can either be ____, ____, or _____

A

soft (acute), hard (chronic), or calcified (under repair)

72
Q

Why does drusen accumulate in the macula more than the fovea?

A

the fovea is protected by pigment

73
Q

Accumulation of Drusen can lead to

A

retinal detachment

74
Q

How does Wet ARMD differ from Dry ARMD?

A

neovascularization in Wet ARMD

75
Q

Aging changes may cause _____ blood flow

A

decreased

76
Q

What transport mechanisms are used to pump ions in and out of the RPE?

A

Na/K
Na/K/Cl co-transport
Na/2HCO3 co-transport
Na/H2O:Lac

77
Q

Most potassium in the retina exist through the ____ ____

A

retinal membrane

78
Q

HCO exits the retina through the ____ _____ in the RPE choroidal membrane

A

Cl/HCO3 exhangers

79
Q

The retinal barrier creates a retina ____ transepithelial potential as a result of transepithelial transport of ion

A

The retinal barrier creates a retina positive transepithelial potential as a result of transepithelial transport of ion

Anatomy and Physio Final (9 decks)

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