Visual System Flashcards
Rod
sensitivity
Black/White
Cone
3 Types (R,G,B)
Concentrated @ Fovea.
Don’t see well at low light
What kind of proteins abosrb light in the eye?
Opsins.
Channel closes when it encounters light
Path of light/nerve signal through retina
Light is abosrbed by cones/rods which propagate the neural signal to biopolar neurons, then ganglion cells which project to the optic nerve
How does information from light move through optical chasm?
temporal visual fields cross to contralateral side
nasal visual fields remain ipsilateral
To which structure does the optic tract project?
Lateral geniculate nucelus (LGN)
In which lobe is the primary visual cortex found?
Occipital
Projection from visual field to brain
superior projets down, inferior projects up
Meyer’s Loop
optic radiation – axons from LGN to primary visual cortex
lateral of lateral ventricles
Diseases and their lesions
How is primary visual cortex organized?
in columns.
Ocular dominance columns (input from left eye vs. right eye)
orientation columns (optimal stimulus is a bar of light of a specific orientation)
Is information integrated together throughout the optical tract?
No, segregation of color information from form and movement information
What is the “where” pathway
from V1 ends in lateral intraparietal area (in macaques)
Where is the “What” pathway
occipitotemporal. ends @ inferior temporal area
