PSY280H5 Lecture Notes - Lecture 4: Retina, Transducin, Phosphodiesterase
Document Summary
Image is showing how much binocular vision we have. humans have ~ 50% of overlap. Duplex organization of the retina: duplex = 2 functionally distinct types of receptors are housed under one roof (the retina, rods ~120 million in the retina, straight shape, cones ~5 million in the retina. Functional segments of rods and cones: outer segment. Light sensitive image/ photo sensitive pigments absorb light: rhodopsin (rods, cone-opsins: each cone opsin has a different spatial sensitivity, difference allows us to see different colours. Inner segment: cytoplasm, mitochondria, nucleus, helps transfers nutrients, resources and pigments to the outer segment, synaptic terminal, where the response is first converted to a signal that can be passed on to other. The fovea: light travels through cells and process to reach photoreceptors, 1-3ses to reach photoreceptors, processes are displayed at fovea, foveal pit reduces light scatter. The resulting image is sometimes called tunnel vision. Can only see the center of the visual field.
