1 Structure Mediates Function Flashcards
what do we need to see?
sampling - get enough photons
analogue to digital - our world is analogue, we convert the signals to digital
noise: stimulus to response - stimuli can be interpreted if enough reduction in noise
how does info from retina give rise to vision?
anatomy/organisation of retina
organisation of retina
photoreceptors
2 synaptic layers (OPL and IPL)
3 cellular layers (GCL, INL, ONL)
glia (muller cells)
layers of retina (internal to external)
ILM NFL GCL IPL INL (bipolar, horizontal, amacrine, Muller) OPL ONL ELM (junction of Muller cells, not real mem) PR RPE
distribution of PR
- centrally?
- peripherally?
- quantity?
central - cones (hexagonal packing)
periphery - rods
rods»_space;> cones
which retinal layer is thicker in central retina?
INL
which retinal layers are thinner in periphery?
the 3 layers below ILM:
NFL
GCL
IPL
which cells participate in vertical pathways?
PR
bipolar cells
amacrine AII cells
GCs
which cells participate in lateral pathways?
horizontal cells
amacrine cells
what wiring patterns are in foveal cones?
one-to-one
what wiring patterns are in parafoveal cones?
diverging
what wiring patterns are in extrafoveal regions?
converging
3 implications of convergent wiring
reduction in # of structures
light sensitivity increases
acuity decreases
why does acuity decrease with convergent wiring?
it becomes difficult to discriminate one cone from another when signals all end in 1 GC
which layer are the on- and off-centre receptive fields located?
IPL
why are receptive fields laid out the way they are?
overlap to ensure all of VF is captured
