NRSC 335 Lecture 17: vision
11 May 2017
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Document Summary
Fovea has highest acuity: o ut towards the peripheral regions, acuity isn"t as good, r etinal anatomy. P hotoreceptors (input: r ods and cones, r ods. S cotopic system: dark, no color, dim light, o utside fovea. C oncentrated in the periphery of the retina. In a dark room, easier to look at object from peripheral vision instead of straight at it (more acuity) Light detecting elements of the eye are furthest away from the light and in fact pointing away from the light. Inhibits receptor and bipolar: horizontal cell, bipolar c ell, amacrine cell. Light sensitive protein - opsin: o psin in retain = rhodopsin. Light photon strikes discs in rod or cone. C leaves rhodopsin into retinal and opsin: o psin activates g protein (transducin, transducin closes na+ channels, hyperpolarizes rod/cone, o ther receptors are normally depolarized and excited, becomes more negative. Isn"t directly polarizing cells, this is an indirect effect through.
