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19 Cards in this Set
- Front
- Back
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How many Rods are there per eye? |
120 Million |
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How many Cones are there per eye? |
6 Million |
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What light-sensitive pigment is present in Rods? |
Rhodopsin (remember both have R's) |
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What Light-Sensitive Pigment is present in Cones? |
Iodopsin |
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Where are Rods distributed in the Eye? |
Peripheries of the Retina, except the Fovea and Blind Spot. |
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Where are Cones distributed in the Eye? |
High Concentration around the Fovea |
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How many types of Rods are there? |
1 |
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How many types of Cones are there? |
3 |
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What Light Intensity do Rods favour? |
Low Intensity. Due to summation, only need low light to Stimulate Bipolar Cells. |
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What Light Intensity do Cones favour? |
High-Intensity. Need bright light to stimulate Bipolar Cells. |
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What is the Visual Acuity of Rods, and why? |
Low. Because multiple Rods are connected to the same Bipolar Cell, some information is lost when Summation occurs, making them less accurate. |
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What is the Visual Acuity of Cones, and why? |
High. Each Cone is connected to it's own Bipolar Cell, meaning all information is retained when an Impulse is sent. |
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How many connections per Bipolar Cell do Rods have? |
Multiple |
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How many connections per Bipolar Cell do Cones have? |
Single |
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Define Retinal Convergence. |
Groups of Rods that converge into a single optic nerve fibre, which increases sensitivity. |
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What is meant by Summation, and how does it occur in the Eye? |
Multiple stimuli trigger a nerve impulse, where one would not. When multiple Rods are stimulated by light, summation occurs to produce an impulse in the Bipolar Cell. |
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What type of Vision do Rods provide? |
Black and White |
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What type of Vision do Cones provide? |
Coloured |
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What directions does the Light and Impulse travel in the Eye? |
Light travels towards the back of the Eye. Impulse travels towards the Middle. |
