The plasma membrane of neuron
when at rest an electric
potential difference its external
and internal . This voltage is
called potential. The resting
potential –70 mV indicates that
interior is more negative the
exterior (negative polarization).
condition is maintained by of
sodium and potassium across the
plasma membrane.

membrane is permeable to
ions but not to ions.
At rest the potassium ions exit
the in favour of the
gradient since within the the
potassium concentration is than
in the extracellular . The positive
sodium ions however go into the
. As positive potassium ions the
cell with not compensation of
positive ions the cell, the
intracellular becomes more
negative and cell stays polarized.