Lecture 29- Thalamus and Striate Cortex Flashcards
Which visual field does the right eye receive information from?
Each eye receives information from both visual fields
Which fibers decussate at the optic chiasm?
fibers of the nasal retina
What would be the result of damage to the right optic nerve? What about the right optic tract?
Right optic nerve damage->lose vision in right eye-maintain vision in both visual fields
Right optic tract damage-> lose vision in left visual field
What results from damage to the optic chiasm region?
bitemporal heminopsia- loss of peripheral vision
What is the role of the suprachiasmatic nucleus (SCN) of the thalamus in the visual system?
some retinal ganglion fibers synapse there at the optic chiasm to provide light/dark input for circadian rhythms
SCN- SLEEP CLOCK
Where are the 4 places that retinal ganglion cells can synapse?
Lateral Geniculate Nucleus (LGN-thalamus)
Superior Colliculus- head movements
Suprachiasmatic Nucleus (SCN-Hypo)- Circaidian
Nuclei of pretectum-pupillary reflex
How many layers are in the lateral geniculate nucleus (LGN)?
6 (2 magnocellular, 4 parvocellular)
What are the two layer sub-types in the LGN?
Magnocellular Layers (inner 2) Parvocellular Layers (outer 4)
Which cells in the LGN are more sensitive to rapidly changing or moving visual stimuli?
M Cells (Magnocellular layers) The have larger bodies and receptive fields
Which cells in the LGN are more sensitive to color and detail?
P Cells (Parvocellular layers) They are slower and more concerned with color and spatial resolution
Which layers of the LGN contain information from the contralateral eye?
1,4,6
Which layers of the LGN contain information from the ipsilateral eye?
2,3,5
What is the primary visual cortex also known as?
striate cortex (V1)
What is the name of the fissure that runs through the striate cortex?
calcarine fissure
Where does input from the two eyes first come together for processing in the visual system?
striate cortex-it is kept separate in the layers of the LGN
