This problem explores what happens to the resting steady state of a membrane, after the ion pumps are suddenly turned off, say by addition of a neurotoxin. namely, sodium ions are far from equilibrium in the resting state. the concentration of sodium inside the cell is 12mm, while outside the cell it is 145mm; the membrane voltage is vmem = -90 mv. this means that when pumps are turned off, sodium will rush into the cell
find the charge per unit length of the axon contributed by all the sodium ions inside the axon (5 points). what would the corresponding quantity equal if the interior concentration of sodium matched the fixed exterior concentration