refractory period

• After an action potential, the sodium and potassium ions are in the wrong places.
• The concentrations of potassium and sodium ions, inside and outside, of the cell must be restored by the action of sodium/potassium ion pumps.
• For a short time after each action potential, it is impossible to stimulate the cell membrane to reach another action potential- this is called the refractory period, it allows the cell to recover after an action potential; it also ensures that action potentials are transmitted only in one direction.