Returning to the Resting Potential
To return to the resting potential from the undershoot, which went to the equilibrium potential of K+, the cell must reset. The inactivation plug is removed from the Na+ voltage-gated channels, and the activation gate is closed. The K+ voltage dependent channels close, stopping the flow of K+ out of the cell. K+ still leaks out of the cell, along with other ions, which causes a resting potential that is slightly higher than the equilibrium potential of K+.
ATPase works to restore the
initial balance of
ions, by moving Na+ out of the cell, and K+ into the cell, against their concentration
gradients. Then Na+ is ready to enter along its gradient
for the creation of an action potential.
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The activation gate closes and the inactivation plug is removed |