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20 Cards in this Set
- Front
- Back
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how does myelin affect the conduction of electrical signals (current)?
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1. it decreases the capacitance, thereby speeds up conduction
2. it creates greater membrance resistance leading to less leaking of current. Thus, increasing the current's length constant. |
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what is capacitance good for in the context of electrical signaling in neurons?
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it leads to temporal summation of EPSPs
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what is the sodium potassium pump?
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it is a protein that moves 3 Na+ ions out of the cell and moves 2 K+ ions into the cell (against their concentration gradient)
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What causes the resting potential?
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-Electrostatic force
-Osmotic force |
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What do the resistors correspond to in a membrane?
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channels mainly
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What is the Nernst Potential?
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It is the potential when the electrical force driving the ion into the cell exactly balances the chemical force driving the ion out of the cell.
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Bigger axon means (more/less)
a. capacitance b. longitudal resistance c. membrane resisistance |
a. more (greater surface which can store charge)
b. less c. less (more ion channels) |
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what does the capacitor correspond to in a membrane?
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a patch of lipid bilayer w/out channels
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what happens to the membrane/input resistance of a neuron if you increase the size of a neuron?`
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you are decreasind the input resistance because there are more resting channels to conduct ions (so that current can flow into the nueron more easily)
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What do voltage-gated ion channesl detect?
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changes i nmembrne potential
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How does an increase/decrease in capacitance affect the speed of current conduction?
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increase in capacitance slows down current conduction
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K+ will tend to diffuse from _________ the cell to __________ the cell.
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inside; outside
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What happens to the capacitance of a neuron if you increase its surface area?
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capacitance goes up
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why is the action potential useful in signaling?
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long distance communication
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Which parts of a neuron has resistance?
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axon and membrane
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What causes the resting potential?
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the separation of charges across the membrane
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What happens if we put a bunch of a K+ outside a cell when the cell is at resting potential?
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it should lead to an influx of K+ into the cell because the electrostatic positive force outside the cell will surpass the electrochemical force trying to push the K+ out of the cell
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what is the membrane for?
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separating the charge so that during depolarization, an AP can be generated
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what is the Nernst potential for: a. K+ b. Na+ c. Cl-
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a. -75mV
b. +55 mV c. -60mV |
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what do ligand-gated ion channels do?
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they are sites for NT binding
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