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Flashcards in B11 Deck (227)
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1

The RPE is a monolayer of pigmented cells, located between _________ and ________

Choriocapillaris and outer segments of photoreceptors

2

The apical membrane of the RPE faces the photoreceptor _______

Outer segments

3

What surrounds the light sensitive outer segments of the RPE?

Long apical microvilli

4

The _____ membrane faces Bruchs membrane

Basolateral

5

Light energy is concentrated on the?

Retina

6

General light absorption occurs via ____ in RPE

Melanin

7

Blue light absorption is supplemented by ___ and ___ in photoreceptors

Lutein and zeaxanthin

8

What is the most dangerous light to the RPE?

Blue light

9

The outer retina is exposed to what kind of environment?

Oxygen rich

10

T/F: The blood perfusion of the choriocapillaris is very high in the outer retina

True

11

Venous blood from the choriocapillaris shows a ___% O2 saturation

90%

12

RPE contains high amounts of superoxide dismutase and catalase

Enzymatic antioxidants

13

RPE accumulates lutein and zeaxanthin, ascorbate, alpha-tocopherol and beta-carotene

Non-enzymatic antioxidants

14

The RPE transports nutrients and metabolic end products
between ______and the _______

Photoreceptors and choriocapillaris

15

Is blood on the apical or basolateral side?

Basolateral

16

Are the photoreceptors on the apical or basolateral side?

Apical

17

The space between RPE and photoreceptors

Subretinal space

18

What are the two ways of transport in the RPE?

Photoreceptors--->blood
Blood--->photoreceptors

19

The transport of water is driven by _______ of Cl- from the retina to blood side

Active transport

20

Describe Bests Vitelliform Macular Degeneration

-Degeneration of RPE
-Bull’s eye shaped lesion
-The lesion primarily contains extracellular fluid
-Reduction in epithelial Cl- transport

21

The transport of lactic acid requires a tight regulation of the ______PH

Intercellular

22

The RPE contains an abundance of what 2 glucose transporters?

GLUT1 and GLUT3

23

An important substance of building membranes of neurons, photoreceptors as well as photoreceptor disk membrane

Docosahexaenoic acid (DHA)

24

What two things are removed from the apical side?

Water and lactic acid

25

The reduction of all-tran retinal into all trans-retinol occurs where?

In photoreceptors

26

Reisomerization of all-trans-retinol into 11-cis-retinal occurs in?

The RPE

27

Describe retinitis pigmentosa

-inherited retinal degeneration
-mutations in genes of the visual cycle
-inability of the RPE to phagocytose photoreceptor outer segments

28

Describe stargardt disease

-retinal degeneration
-mutations in the genes of the visual cycle

29

The process of phagocytosis is under what kind of control?

Circadian control

30

What triggers phagocytic activity?

The onset of light in the morning