Visual Pathways - week 11 Flashcards
Layers of LGN from Inner to outer?
Can I Imagine Cats In Canada (Contra, Ipsi, Ipsi, Contra, Ipsi, Contra)
First 2 layers are Magnocellular layers, next 4 are parvocellular layers
What layer is between magnocellular and parvocellular layer?
Koniocellular layer
Where do the parvocellular layers get input from?
Midget cells
Where doe the Magnocellular layers get input from?
Parasol cells
How large is the Magno receptive field?
Large
Describe Magno contrast sensitivity?
High
Describe Magno spatial resolution?
Low
Which is better for detecting motion? Magno or Parvo?
Magno. Because it is a transient response
How large is Parvo receptive field?
small
Describe Parvo contrast sensitivity?
Lower
Describe Parvo spatial resolution?
High spatial resolution
Where does Magno project to?
Layers 4Calpha and lower 6 in area V1
Where does Parvo project to?
Layers 4Cbeta and upper 6 in V1
Which pathway mediates red/green colour vision? Magno or Parvo?
Parvocellular pathways
Which pathway is best sensitive to motion? Magno or Parvo?
Magnocellular cells are sensitive to motion
Which has faster conduction velocity? Magno or Parvo?
Magnocellular (because bigger myelin sheathe)
What signals do Koniocellular cells carry?
Short-wavelength sensitive signals from the cones
Which pathway is involved with blue/green discrimination?
Koniocellular pathway
To which layers in LGN do parasol retinal cells project?
(= magnocellular pathway) so layers 1-2
To which layers in LGN do midget rGCs project?
3-6
What retinal ganglion cell type carries S cone signals? Which LGN regions do they project to?
Short bistratified
- project to koniocellular
Which LGN layers transmit red/green signals?
3-6
Which LGN layers transmit blue/yellow signals?
koniocellular
What is blindsight?
Ability to respond to visual stimuli without consciously perceiving them (can occur after type of brain damage)
What sort of visual field defect does a lesion in the optic chiasm cause?
Bitemporal Homonymous Hemianopia
Which of the following pass through superior orbital fissure? A) ophthalmic nerve B) Oculomotor nerve C) optic nerve D) trochlear E) abducencs F) ophthalmic vein
Trochlear apparently
