Term
| -60(smooth muscle) - -90 mV(neurons) |
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Definition
| normal cell electrical potential difference |
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Term
| the membrane potential that balances the ionic concentration gradient |
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Definition
| what is the equilibrium potential for an ion |
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Term
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Definition
| what potential must the cell have to keep K+ from moving out? |
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Term
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Definition
| what potential must the cell have to keep sodium from flowing in? |
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Term
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Definition
| what is the eq potential for K+ |
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Term
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Definition
| what is the eq potential for Na+ |
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Term
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Definition
| what is the eq potential for Ca2+ |
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Term
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Definition
| what is the eq potential for Cl- |
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Term
E ion = (61.54/z) log ([ion o/ion i])
z is charge of the ion |
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Definition
| what is the simplified nernst equation assuming 37 degrees celcius? |
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Term
| eq potential for multiple ions |
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Definition
| what does the goldman equation tell you? |
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Term
| Vm = 61.54 mV log (Pk[k+]o + Pna[Na+]o + Pcl[Cl-]i ////// Pk[K+]i + Pna[Na+]i + Pcl [Cl-]o |
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Definition
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Term
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Definition
| at rest, which ion has greater permeability? K+ or Na+ |
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Term
| K+ establishes resting membrane potential between -60 and -90 mV |
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Definition
| if the cell is at rest, what ion eq potential is closest? |
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Term
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Definition
| rapid change in potential from - to + to - again, combination of excitatory and inhibitory signals |
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Term
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Definition
| where is the graded potential? |
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Term
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Definition
| where is the action potential? |
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Term
| excitatory post synaptic potential |
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Definition
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Term
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Definition
| what opens ion channels on dendrites? |
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Term
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Definition
| if a sodium channel is opened, to what potential will the ions flow in as long as the channel is not voltage gated? |
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Term
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Definition
| what ion does depolarization depend on? |
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Term
| voltage gated potassium channels |
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Definition
| what ion does repolarization depend on? |
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Term
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Definition
| how fast particular ions can move |
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Term
| rapid closing of sodium channels does not allow this |
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Definition
| why don't action potentials move backwards? |
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Term
| absolute refractory period |
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Definition
| inactivation gates of Na+ closed, neuron cannot be stimulated |
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Term
| relative refractory period |
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Definition
| need a stronger stimulus to initiate a response |
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Term
once threshold of excitation is met,
1. na open, na enters cell
2. K channels open, k begins to leave the cell
3. na channels become refractory(inactivation gate closed) no more na flows in
4. k continues to leave the cell causing membrane potential to return to resting level
5. k+ channels close, Na channels reset
6. extra K+ outside diffuses away |
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Definition
| describe the Na/and K channels throughout the action potential |
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Term
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Definition
| faster way to travel down an axon than without myelin "to leap", signals travel node to node |
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Term
| Lidocaine and Tetrodotoxin |
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Definition
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Term
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Definition
| can stabilize Na current, or cause increase excitability |
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