Pathways In The Retina

Pathways In The Retina

1. Ganglion cells axons form optic nerve

   • First synapse in the LGN of the thalamus, two distinct pathways
     • 4 Parvocellular layers
       • Small RF's in fovea, sustained response and sensitive to cellular detail
     • 7 Magnocellular layer
       • Large RF's in periphery, brief responses and sensitive to movement and outline of shape

2. Vision is generated by photoreceptors in the retina, a layer of cells at the back of the eye

   • information leaves the eye by way of the optic nerve, and there is a partial crossing of axons at the optic chiasm
     • The optic tract wraps around the midbrain to get to the lateral geniculate nucleus (LGN), where all the axons must synapse. From there, the LGN axons fan out through the deep white matter of the brain as the optic radiations, which will ultimately travel to primary visual cortex, at the back of the brain.