Term
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Definition
Diuretic drug. Blocks the Epethelial Na Channel (ENaC) Less Na gets in the cell so water leaves to go towards higher osmolarity. |
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Term
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Definition
Diuretic drug Blocks Na/Cl cotransporter Water leaves towards higher osmolarity |
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Term
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Definition
Diuretic Drug Blocks Na2ClK cotransporter Kidney(loop of Henle) Water leaves the cell towards higher osmolarity |
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Term
Common apical transporters |
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Definition
CoTransporters: Na/Glucose, Na/AA, Na/Phosphate or Lactate or Citrate, CounterTransporter: Na/H, K/H, 2Na/Ca Channel: Na |
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Term
| Basal Lateral transporters or channels |
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Definition
CounterTransport: 3Na/2K Channel: Glucose, AA, Phosphates or lactase or citrate, HCO3- |
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Term
| What do Action Potentials have that Electronic Potentials don't? |
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Definition
Threshold Active, all-or-none conduction All-or-none same amplitude Chemical or Mechanical stimulus Polarity inside is positive (+) Self regenerating Propagates(down axon) Refractory period No temporal or spacial summation(multiple signals are not combined) |
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Term
| Which part of the Action Potential does positive feedback play a role? |
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Definition
During the Rising phase. Na+ influx depolarizes the membrane and stimulates opening of Na+ channels |
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Term
| During which phase of action potential is Na conductance at its greatest? |
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Definition
Overshoot membrane potential becomes a (+) number |
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Term
| What are the gates doing at the peak of the action potential? |
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Definition
The initial Na channels that opened are starting to close. K channels are starting to play a bigger role. |
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Term
| During what phase of action potential is K conductance at it's greatest? |
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Definition
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Term
| During what phase of action potential is the K conductance decreasing? |
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Definition
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Term
| What do Tetrodotoxin (TTX) and Saxitoxin do? |
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Definition
Block voltage Na channels Saxitoxin is found in the sea. Leads to no action potential. |
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Term
| What does Tetraethylammonium (TEA) do? |
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Definition
Block voltage K channels leads to longer action potentials. |
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Term
| What are the 2 gates on the Na voltage channel? |
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Definition
Activation gate: Located on the extracellular surface. It is closed during resting state. It opens when the membrane potential rises to about -45mv. It won't close until the membrane potential is returned to normal levels. Inactivation gate: Is open at resting state. Closes after the activation gate has been open for a certain amount of time. Opens back up when the other gate closes. |
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Term
| How does the gate of the K voltage channel act? |
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Definition
It is located in the intracellular surface of the cell. It opens when the membrane potential is above the threshold. It closes once the membrane potential returns below the threshold. |
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Term
| Absolute refractory period. |
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Definition
First 3/4 of the action potential. Can't trigger another action potential because Na channels are closed. |
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Term
| Relative refractory period |
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Definition
Enough Na channels are in rest state to recruit some. Threshold is higher so it requires a bigger stimulus. Amplitude will not be the same. |
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