In a neuron at rest, the intracellular K+ concentration is t…
In a neuron at rest, the intracellular K+ concentration is typically about 110 mM, and the extracellular K+ concentration is typically about 4 mM. For sodium, the intracellular and extracellular Na+ concentrations at rest are about 10 mM and 130 mM, respectively. At the peak of the action potential when the membrane potential approaches +30 or +40 mV the: