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15 Cards in this Set
- Front
- Back
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What part of the eye contains photoreceptors?
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The retina
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Define photorecpetors
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Specialized neuron found in the eye capable of undergoing phototransduction. We have two types, rods and cones.
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How do rods enable our vision?
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It enables us to see at night, but only in black and white. Most sensitive photoreceptor, have a single pigment, and are not very accurate in vision
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What are cones?
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It is the photoreceptor that is responsible for color vision. Densely packed in the fovea and spread out in the retina. Contributes to very poor night vision.
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There are three different types of proteins in the cones that produce what three colors?
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red, blue, and green
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Where do people who are color blind have a mutation?
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in the cone. It is sex linked and affects mostly males.
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Define Fovea
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No rods. Only cones. It just goes directly to photoreceptors and not all the other neurons so this is the clearest picture.
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rods and cones contain what visual pigments?
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retinal (light absorbing molecule) Which is bound to opsin (a membrane protein). Together they make up the visual pigment rhodopsin
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Retinal is a derivative of what vitamin?
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Vitamin A. A deficiency of vitamin A can lead to night blindness
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What is bleaching?
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absorption of light changes conformation of retinal from cis to trans arrangement (from a kink to a straight shape).
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What kind of channels do rods have?
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they have Na+ channels that are chemically gated.
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Pigment epithelium prevents what?
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Light passes all the other layers to reach the very back of the retina.
-It prevents light from bouncing or reflection |
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When do rods and cones release glutamate to the bipolar cells?
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In the dark, rods and cones depolarized and continuously release neurotransmitter glutamate to the bioplar cells.
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Explain Horizontal cells.
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involved in signal transmission and sharpens image; spreads signals horizontally and not straight
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Explain Amacrine cells.
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Involved in signal processing. Some are excitatory and some are inhibitory. This causes sharpness in the edges of our vision.
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