The Concentration of Sodium Is Greater in the Extracellular Fluid

Multiple Choice

The concentration of sodium is greater in the extracellular fluid compared to the intracellular fluid. If the membrane potential was equal to the equilibrium potential for sodium, then what would be the direction of the electrochemical force acting on sodium?

A) inward
B) outward
C) equal in both directions
D) varies by cell
E) varies based on concentration of potassium in the intracellular and extracellular fluids