(Science: physiology) The electrical potential of the inside of a cell, relative to its surroundings. Almost all animal cells are negative inside, resting potentials are in the range 20 to 100mV, 70mV typical.
resting potentials reflect the action of the sodium pump only indirectly, they are mainly caused by the subsequent diffusion of potassium out of the cell through potassium leak channels. The resting potential is thus close to the nernst potential for potassium.
See: action potential.