Lecture 10: 12/15 Flashcards
describe how the retina transduces light
it turns light into a neurochemical signal for sight
embryology of the retina: it is derived from the:
forebrain, derived from neural ectoderm
describe the 2 aspects to the retina
- neural: transduction of the light energy to biochemical signal, processing, and transmission to visual cortex
- non-neural: involved in maintenance, support, nutrition
the retina is ___ layers thick
10
light has to go through ___ layers in the retina before it gets to the layer where transduction takes place
8
thickness of the retina is ____ mm
0.37 mm
layer 1 (most exterior) of the retina
retinal pigment epithelium (RPE)
layer 2 of the retina
receptive segments (rods and cones)
layer 3 of the retina
external limiting membrane (ELM)
layer 4 of the retina
outer nuclear layer (ONL), cell body layer
layer 5 of the retina
outer plexiform layer (OPL), outer synaptic layer
layer 6 of the retina
inner nuclear layer (INL), bipolar cell layer
layer 7 of the retina
inner plexiform layer (IPL), inner synaptic layer
layer 8 of the retina
ganglion cell layer
layer 9 of the retina
nerve fiber layer (NFL)
layer 10 of the retina
internal limiting membrane (ILM)
neurologists classify layers 1-5 of the retina as the
receptor layer
neurologists classify layers 5-7 of the retina as the
primary neuron of the retina
neurologists classify the layers 7-10 of the retina as the
secondary neuron of the retina
location of the RPE is next to the
choroid
cell type in the RPE
wide cells and not very tall
the RPE is attached to ______ membrane
Bruch’s
functions of the RPE are
- an irregular surface for ends of receptive segments
- dark to decrease scatter
- storehouse for vitamin A
phagocytic role of the RPE is
recycles photopigments by ingesting
pigment in the RPE is from
melanin and lipofuscin (which is thought to be a byproduct of metabolism of the photoreceptors)
nucleus of the RPE cells is on which end of the cell
the basal end
pigment of the RPE cells is on which end of the cell
the apex
cytoplasmic extensions in the RPE are at what end of the cell
the apical end
adjacent lateral cell walls at the basal end of the cells are joined by:
zonula occludens
describe the role of the zonula occludens in the RPE cells
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
the zone occludens and desmosomes at the basal end of the RPE cells forms a membrane called the
membrane of Verhoff
role of the membrane of Verhoff in the RPE
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
a retinal detachment is actually a split between the ___ and _____
RPE and the rod and cone layer
what is a weak attachment that can lead to retinal detachments
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
