PHSI2005 Final: vision

• School: University of Sydney
• Department: Physiology
• Course: PHSI2005
• Professor: phsi2005

Document Summary

Fovea receptor layer not covered by other retinal neurons (vision most acute) when object fixated its image is formed here. Increase in glutamate release onto ganglion cells, resulting in its depolarisation (cid:198) Increased firing of impulses which propagate out along axons, along optic nerve, to the lateral geniculate nucleus of the thalamus. Receptive fields and responding of ganglion cells (contrast sensitive units) (respond best when maximum contrast between centre and surround) (cid:120) (cid:120) e. g. bright centre spot + dark annulus (ring) (cid:120) spot of light onto cat. All sensory medullas go through the thalamus, except smell. Part of the thalamus responsible for vision is the lateral geniculate nucleus. The visual field of one side of the brain remains on that same side. Striate cortex of left cerebral hemisphere (cid:120) horizontal neurons fire at the lips (since horizontal) (cid:120) vertical neurons fire at the edge of the hair/face.