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47 Cards in this Set
- Front
- Back
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in retina, ___ (2) cells do not fire action potentials, but ___ cells do
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photoreceptors
bipolar ganglion |
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in retina, ___ cells have center-surround antagonism due to ___ (2) cells
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bipolar
horizontal amacrine |
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2 parts of receptive field
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center
surround |
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2 kinds of center-surround antagonism
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on-center
off-center |
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in off-center cells, light on ___ of ___ causes suppression
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center
RF |
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2 kinds of ganglion cells
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parasol
midget |
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parasol cells are aka ___ (2)
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Palpha
A |
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midget cells are aka ___ (2)
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Pbeta
B |
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parasol cells have ___ cell bodies, ___ receptive fields, and respond preferentially to ___ (2)
they project to ___ LGN layers |
big
big gross features and movement magnocellular |
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midget cells have ___ cell bodies, ___ receptive fields, and respond preferentially to ___ (2)
they project to ___ LGN layers |
small
small fine detail color parvocellular |
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2 pathways in optic tracts
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geniculate
extrageniculate |
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extrageniculate fibers synapse in ___
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pretectal region
superior colliculus |
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LGN layers are numbered from ___ to ___
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ventral
dorsal |
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layers 1-2 of LGN are ___, layers 3-6 are ___
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magnocellular
parvocellular |
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lateralization of layers of LGN
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1: contra
2: ipsi 3: ipsi 4: contra 5: ipsi 6: contra |
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fovea maps to ___ part of V1
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most posterior
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medial occipital lobe above calcarine fissure is called ___
below is called ___ |
cuneus
lingula |
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3 modalities in visual pathway
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location/motion
form color |
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V1 is defined histologically via ___
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stria of gennari
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with Nissl stain, stria of gennari are visible as ___
they look like that because of ___ |
pale stripe (layer 4B) in between layers 4A and 4C
myelin |
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location/motion information is transduced by ___ cells,
relays in ___ LGN, synapses in layer ___ of V1, projects to layer ___ in V1, projects to ___ in V2, and to ____ |
parasol
magnocellular 4Calpha 4B thick stripe dorsolateral parieto-occipital cortex |
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form information is transduced by ___ cells,
relays in ___ LGN, synapses in layer ___ of V1, projects to layer___ in V1, projects to ___ in V2, and to ____ |
midget
parvocellular 4Cbeta 2, 3 (interblobs) pale stripe inferior occipito-temporal cortex |
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color information is transduced by ___ cells,
relays in ___ LGN, synapses in layer ___ of V1, projects to layer___ in V1, projects to ___ in V2, and to ____ |
midget
parvocellular 4Cbeta 2, 3 (blobs) thin stripe inferior occipito-temporal cortex |
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V1 layer 4 cells have ___ receptive field
2 kinds of cells with more complicated RFs are ___ they are located in ___ |
center-surround
simple cells complex cells layers above and below 4 |
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simple cells respond to ___
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edge in specific location with specific orientation
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complex cells respond to ___
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edge with specific orientation in any location
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formed visual hallucinations localize to ___
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inferior temporo-occipital cortex
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2 kinds of pre-chiasmal ischemia
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retinal ischemia
ischemic optic neuropathy |
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2 causes of retinal ischemia
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central retinal artery occlusion
branch retinal artery occlusion |
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occlusion of a branch retinal artery causes a ___ field cut
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altitudinal monocular
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retinal TIA is aka ___
it is classically presents as ___ common etiology is ___ |
amaurosis fugax
curtain descending over visual field ipsilateral ICA stenosis |
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2 kinds of ischemic optic neuropathy
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anterior
posterior |
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AION affects optic nerve at ___
it is caused by occlusion of ___ |
optic nerve head
short posterior ciliary arteries |
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2 kinds of AION
___ is more common |
arteritic
non-arteritic non-arteritic |
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arteritic AION is caused by ___
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GCA
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non-arteritic AION is caused by ___
___ is a fundoscopic risk factor |
DM
HTN atherosclerosis small cup-to-disc ratio |
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non-arteritic AION classically presents at ___, due to ___
vision loss is ___ |
upon awakening
hypotension painless |
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PION affects optic nerve at ___
it is caused by occlusion of ___ |
retrobulbar portion
pial branches of ophthalmic artery |
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2 kinds of PION
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arteritic
post-op |
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arteritic PION is caused by ___
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GCA
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in contrast to retinal ischemia or ION, visual disturbance in optic neuritis is ___
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central scotoma
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3 fundoscopic findings in optic neuritis
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disc swelling (papillitis)
disc pallor (if not first episode) normal fundus if inflammation is retrobulbar |
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2 physical exam findings in optic neuritis
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red desaturation
APD |
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evoked potential finding in optic neuritis
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prolonged latency of VEP with preserved amplitude (demyelination)
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optic neuritis presents over ___
resolution typically occurs over ___ IV steroids causes ___ but not ___ |
hours to weeks
6-8 weeks decreased duration of symptoms long-term outcome |
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workup optic neuritis if ___ (4)
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age>45
lack of eye pain bilateral sx delayed recovery |
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workup for optic neuritis (7)
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MRI with Gd
ESR lyme RPR EBV HIV B12/folate |
