Cell biology and neuroscience resting and action potential PDF

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) is around -70 Vm. The for an ion is the e that needs to be able to prevent movement of that ion down its concentration . If inside is very negative it will stop K ions from leaving If inside is very positive it will stop Na ions from entering. : - EK = -90 mV - ENa = Vm is much closer to EK than ENa because membrane is about 50 times more permeable to K ions and Na ions. At constant Vm net flow of ions is zero because the passive leak of K ions is matched by leak of Na ions.

electrochemical gradient and will drive Vm towards the equilibrium potential for that ion. .

Relative permeability and conductance infects the voltage of membrane at rest as well. - Membrane with more channels have high conductance

1. Action potential is triggered by . 2. Threshold of depolarisation required for Action potential 3. e 4. Propagates without decrement 5. At peak: . 6. After action potential membrane is in excitable during refractory period. Action potential is current flow through voltage-gated sodium and potassium channels. Channels are ion-selective and open or closed. Probability of opening and closing is determined by the voltage across the . Membrane becomes permeable to Na ions first then Potassium...