NEUR 3200 Lecture Notes - Lecture 14: Heterotrimeric G Protein, Ligand-Gated Ion Channel, Transducin
8 Mar 2016
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Document Summary
Optic disk (no photoreceptors and is bases of blind spot) Shape: 3mm oval spot with yellow pigment near middle of retina. Most of our cones and lower ratio of # of photreceptors to ganglion cells. Light has to travel through all the cells to reach the photoreceptrs. Cell bodies move aside and therefor light can reach photreceptors faster. One to one ratio of photoreceptor and ganglion cells. Pigment epithelium: contains melanin to prevent back scattering of light. To prevent light bounding backwards after it goes to the retina. Any photons that are not observed are absorbed by the pigment epithelium. 3 main functions: limit back scattering of light by melanin, remove old pigment disks by phagocytosis from tip of the photoreceptor (disk only last for 12 days, regenerate photo pigment molecules after exposure to light. 5 classes of neurons: photoreceptors (most direct)
