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15 Cards in this Set
- Front
- Back
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What is the process that allows the transfer of information between and within cells and their effectors?
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Excitability
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Define the means of electrical signals between cells and effectors
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action potential
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Define the cell type that is able to produce an action potential
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excitable cells (includes nerves and all types of muscle)
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In broad terms, what is an action potential?
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a reversal of membrane potential and the means in which all neuronal information is carried and encoded
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What initiates an action potential?
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various forms of stimuli
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Is there variation in the amplitude of an action potential?
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No, they are all of none. Every action potential has the same amplitude.
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How is an action potential initiated?
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when the stimulus depolarizes the cell to threshold.
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(T or F) AP's are actively regenerated as they are conducted along a cell
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True
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(T or F) Electrical signals (non-AP's) decay with distance from the stimulus due to passive diffusion
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True
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What is the limiting property of action potential frequency?
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Refractoriness
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Can a cell initiate another AP in the absolute refractory period? Relative?
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No; yes
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Define the events during the following:
Depolarization Repolorization |
Inward flow of Na+ (cell becomes more positive)
Outward flow of K+ (cell becomes more negative) |
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Explain how the cell becomes more negative by conducting an outward flow of K+
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Potassium has a NEGATIVE Nerst potential and therefore generates a negative current when passed through the membrane
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(T or F) A large amount of ions need to be displaced from the cell in order to change the membrane potential
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Super False, only very few ions need be displaced
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What mechanism helps the cell to restore ion gradients after and action potential?
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Na+/K+ ATPase
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