Lecture 10: 12/15

Question 1

describe how the retina transduces light

Answer 1

it turns light into a neurochemical signal for sight

Question 2

embryology of the retina: it is derived from the:

Answer 2

forebrain, derived from neural ectoderm

Question 3

describe the 2 aspects to the retina

Answer 3

• neural: transduction of the light energy to biochemical signal, processing, and transmission to visual cortex
• non-neural: involved in maintenance, support, nutrition

Question 4

the retina is ___ layers thick

Answer 4

10

Question 5

light has to go through ___ layers in the retina before it gets to the layer where transduction takes place

Answer 5

8

Question 6

thickness of the retina is ____ mm

Answer 6

0.37 mm

Question 7

layer 1 (most exterior) of the retina

Answer 7

retinal pigment epithelium (RPE)

Question 8

layer 2 of the retina

Answer 8

receptive segments (rods and cones)

Question 9

layer 3 of the retina

Answer 9

external limiting membrane (ELM)

Question 10

layer 4 of the retina

Answer 10

outer nuclear layer (ONL), cell body layer

Question 11

layer 5 of the retina

Answer 11

outer plexiform layer (OPL), outer synaptic layer

Question 12

layer 6 of the retina

Answer 12

inner nuclear layer (INL), bipolar cell layer

Question 13

layer 7 of the retina

Answer 13

inner plexiform layer (IPL), inner synaptic layer

Question 14

layer 8 of the retina

Answer 14

ganglion cell layer

Question 15

layer 9 of the retina

Answer 15

nerve fiber layer (NFL)

Question 16

layer 10 of the retina

Answer 16

internal limiting membrane (ILM)

Question 17

neurologists classify layers 1-5 of the retina as the

Answer 17

receptor layer

Question 18

neurologists classify layers 5-7 of the retina as the

Answer 18

primary neuron of the retina

Question 19

neurologists classify the layers 7-10 of the retina as the

Answer 19

secondary neuron of the retina

Question 20

location of the RPE is next to the

Answer 20

choroid

Question 21

cell type in the RPE

Answer 21

wide cells and not very tall

Question 22

the RPE is attached to ______ membrane

Answer 22

Bruch’s

Question 23

functions of the RPE are

Answer 23

• an irregular surface for ends of receptive segments
• dark to decrease scatter
• storehouse for vitamin A

Question 24

phagocytic role of the RPE is

Answer 24

recycles photopigments by ingesting

Question 25

pigment in the RPE is from

Answer 25

melanin and lipofuscin (which is thought to be a byproduct of metabolism of the photoreceptors)

Question 26

nucleus of the RPE cells is on which end of the cell

Answer 26

the basal end

Question 27

pigment of the RPE cells is on which end of the cell

Answer 27

the apex

Question 28

cytoplasmic extensions in the RPE are at what end of the cell

Answer 28

the apical end

Question 29

adjacent lateral cell walls at the basal end of the cells are joined by:

Answer 29

zonula occludens

Question 30

describe the role of the zonula occludens in the RPE cells

Answer 30

they are tight junctions practically bridging the intercellular space in a circle around each cell, and theycollectively form a net with the cells ticking through the mesh

Question 31

the zone occludens and desmosomes at the basal end of the RPE cells forms a membrane called the

Answer 31

membrane of Verhoff

Question 32

role of the membrane of Verhoff in the RPE

Answer 32

acts as a major barrier to the movement of ions and chemical substances from the choroid to the outer retina, contributing to the so called blood-retina barrier

Question 33

a retinal detachment is actually a split between the ___ and _____

Answer 33

RPE and the rod and cone layer

Question 34

what is a weak attachment that can lead to retinal detachments

Answer 34

the RPE is firmly attached to Bruch’s membrane of the choroid, but the attachment of the rods and cones to the RPE is weak