Vision Flashcards
where is the central fixation point in vision?
fovea with highest visual acuity
what are rods for?
low light vision, there are lots of them
What are cones for?
there are less, but they are mostly in the fovea and have high spatial and temporal resolution and color vision
what are parasol cells for and what do they look like? where do they project?
large cell bodies with large receptive / dendritic fields to respond to gross movement / feature. Large diameter fibers project to magnocellular layers of LGN in thalamus
what are midget cells for and where do they project?
small cell bodies and fibers project onto parvocellular layers of LGN. Good for fine visual details and colors
what are the two main visual pathways and what are they for?
- extrageniculate: retino-tecto-pulvinar-extrastriate cortex: visual attention and orientation (less fibers)
- retino-geniculate-striate pathway: visual discrimination and perception
what is the pretectal area for?
pupillary light reflex: projects to PNS nuclei controlling pupils
what is the superior colliculus and pretectal area for?
visual attention and eye movements toward visual stimuli. Project to pulvinar and lateral posterior nucleus of thalamus for this
what layer of visual cortex receives the most input?
Layer 4 stria of gennari (striate cortex)
What are the two main visual association cortices?
Where: dorsal pathway to parieto-occipital region
What: ventral pathway to temporo-occipital region
visual hallucinations in what two neuro diseases?
CJD and Lewy body dementia
rainbow halos in what disease?
acute glaucoma
light flashes in what eye problem?
retinal detachment
