Repolarization of the Membrane Potential
The membrane potential at the peak of the Action Potential trace corresponds closely to
the equilibrium potential of Na+.
Once the membrane potential has become positive enough to reach this point (at the equilibrium
potential of Na+), the
Na+ voltage-gated ion channel closes by the movement of the inactivation particle (tethered
plug) into the
channel, and Na+ stops moving into the cell. At the same time, K+ voltage-dependent
channels open and
K+ leaves, repolarizing that section of the cell.
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The activation gate is open and the inactivation plug closes the channnel |