Visual Pathways (Lecture #12) Flashcards
anopsia
no vision
hemianopsia
no vision in 1/2 of visual field
homonymous hemianopsia
loss of vision in same 1/2 of visual field in both eyes
first neuron in the visual pathway; gets stimulated by photoreceptors; lies entirely within retina
bipolar cell
second neuron in visual pathway; axons make up optic nerve, chiasm, and tract
ganglion cell
where is cell body of third neuron in visual pathway
lateral geniculate nucleus of thalamus
what do the axons of the third neuron in the visual pathway form?
optic radiations
where does the 4th neuron in the visual pathway lie?
primary visual cortex
meyer’s loop
axons representing the inferior 1/2 of the retina that swoop down into the temporal lobe
superior bank of primary visual cortex represents what part of retina
superior portion of retina
inferior bank of primary visual cortex represents what part of retina
inferior portion of retina
lesion before optic chiasm will cause
loss of vision in one eye
lesion at optic chiasm of decussating neurons will cause
bitemporal visual field loss
lesion after the chiasm will cause
contralateral visual field loss in both eyes (homonymous hemianopsia)
lesion in Meyer’s loop or in inferior bank of the calcarine fissure will cause
homonymous superior quadrantanopsia