Physiology Or RPE And Retinal Blood Barrier

Question 1

Apical side of RPE

Answer 1

Photoreceptor side

Question 2

Basal side of RPE

Answer 2

BM of RPE from Bruchs

Question 3

Where does general light absorption occur

Answer 3

Melanin in RPE

Question 4

Blue light absorption

Answer 4

Supplemented by late in and zeaxanthin in photoreceptors

Question 5

Most dangerous light for RPE

Answer 5

Blue light

Question 6

Outer retina exposed to

Answer 6

Oxygen rich enovironment

Question 7

Outer retina and oxidative damage

Answer 7

Susceptible to it since it is in the presence of the choriocapillaris blood supply

Question 8

Line of defense against oxidative damage to the retina

Answer 8

RPE

Question 9

Transepithelial transport RPE

Answer 9

1. Transport from photoreceptors to blood

2. Transport from blood to the photoreceptors

Question 10

Apical side of RPE

Answer 10

Photoreceptors (subretinal space between RPE and photoreceptors)

Question 11

Basolateral side of RPE

Answer 11

Blood

Question 12

Removal of water from apical side

Answer 12

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

Question 13

What happens when going from photoreceptors to blood

Answer 13

1. Removal of water from apical side

2. Removal of lactic acid from apical side

Question 14

Degeneration of RPE, bulls eye shaped lesion, the lesion primarily contains extracellular fluid. Caused by reduction in epithelial Cl- transport

Answer 14

Best’s Vitelliform macular degeneration

Question 15

Transport of lactic acid from RPE

Answer 15

Requires a tight regulation of the intracellular pH

Question 16

What transports nutrition from blood to photoreceptors?

Answer 16

RPE

Question 17

Transports and RPE

Answer 17

Contains a lot of transporters to transport glucose to the photoreceptors

Question 18

Things the RPE can transport into the photoreceptors

Answer 18

All-trans-retinol, glucose, DHA

Question 19

Visual cycle

Answer 19

• reduction of all-trans-retinal into all-trans-retinol occurs in photoreceptors
• reisomerization of all-trans-retinol into 11-cis-retinal
• occurs in RPE

Question 20

Where does reduction of all-trans-retinal happen

Answer 20

Photoreceptors

Question 21

Here does reisomerixation of all-trans-retinol occur

Answer 21

RPE

Question 22

Inherited retinal degeneration caused by mutations in genes of the visual cycle

Answer 22

Retinitis pigmentosa

Question 23

Retinal degeneration caused by mutations int he genes of the visual cycle

Answer 23

Stargardt disease

Question 24

The process of phagocytosis is under what control

Answer 24

Circadian

Question 25

When is phagocytosis at its peak in the RPE

Answer 25

Morning

Question 26

Every RPE cell is facing an average of ______ photoreceptors in the fovea

Answer 26

23

Question 27

Inability of the RPE to phagocytosis photoreceptors outer segment

Answer 27

RP

Question 28

What does RPE secrete into the photoreceptors

Answer 28

PEDF VEGF Other growth factors Cytokines or immune modulators

Question 29

VEGF in healthy eyes

Answer 29

Secreted in low concentrations

Question 30

What is essential for maintenance of the structural integrity of retina?

Answer 30

Other factors (not PEDF or VEGF)

Question 31

The most severe complication in age related macular degeneration. RPE cells secreted VEGF at a higher rate compared with RPE cells from eyes without neovasculariation

Answer 31

Choroidal neovascularisation

Question 32

Retinal blood barrier

Answer 32

Retinal vascular endothelium | Tight junction between retinal pigment epithelium

Question 33

Which option stand for apical side, basolateral side of RPE

Answer 33

Photoreceptor, choriocapillaris

Question 34

Which option absorbs blue light

Answer 34

Lutein and zeaxanthin

Question 35

Which one is driving force to remove water from apical side

Answer 35

Active transport of Cl- from retina to blood

Question 36

Where does reisomerization of all-trans-retinol into 11-cis-retinal occur

Answer 36

RPE

Question 37

Which disease is due to reduction of epithelia Cl- transport

Answer 37

Bests vitelliform macular degeneration

Question 38

Which growth factor gets involved in choroidal neovascularization

Answer 38

VEGF