C_S_D 4430 Lecture Notes - Lecture 31: Prosopagnosia, Lateral Geniculate Nucleus, Thalamus
Document Summary
Photopigments: term given to the receptor protein found in rods and cones. There are three different types of photopigments found in cones (only need to know the one) The one photopigment found in rods is called rhodopsin. In absence of light, retinal is bound to rhodopsin. Na ion channels open and rods are depolarized. When light strikes the retina, retinal changes shape, temporarily closing. Although the first step in visual sensation is inhibitory, it leads to an increased chance of an action potential being generated in the optic nerve (ganglion cells) Lateral halves of eat retina temporal hemiretinas. The nasal hemiretinas receive the lateral portion of the visual field and the temporal hemiretinas receive the medial portions of the visual field. Axons of the nasal hemiretinal ganglion cells decussate at the optic chiasm; and. Axons of the temporal hemiretinal ganglion cells travel through the optic chiasm ipsilaterally.
