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14 Cards in this Set
- Front
- Back
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there are 2 kinds of electrical
signals what are they |
graded potential and action potential
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graded potentials occur where
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in the cell body and dendrites
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the magnitude of a graded potential is reflected by??
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intensity or strength of the stimulus
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the strength of the initial depolarization in a graded potential is determined by ??
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how much charg (Na+) enters the cell
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what happen to signals when they travel a short distance??
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they loose strength as they travel thru the dendrite.
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action potiential is?
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nerve impulse
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what causes change im membrane potential to occure?
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at threshold the Na+ gate opens
memory potential goes-70 to +30 |
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during depolarization???
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activation gate opens
inactivation gate closes w/delay as long as cell remains depolarized the act-gate is open |
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what is repolarization phase?
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just befor the Na+ channels close (inactivated) the K channels fully open and repolarizes back to RMP
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after an AP, Na+/K+ pump extrudes Na+ what happens
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K+ is recovered...thus will reverse
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what is repolorization?
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K+ moves out cell to extracellular fluid
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what is relative refractory period
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when gate is still open so the cell is not back to normal..
vg k+ channels r open so its harder to depolarize. |
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absolute refractory ?
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depends on time. If enough channels are closed rather than inactived a stimulus can happen.
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what is good about a milonsheet
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it makes rx faster and prevents loss of the charge.
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