Nervous System Transmission of impulse

4) Final phase of action potential is UNDERSHOOT OR HYPERPOLARIZATION Membrane permeability to K+ is higher than at rest All Na+ volt. gat.channels are closed Some K+ are opened, but eventually closed, so that the neuron returns back to rest.

During the REFRACTORY PERIOD no impulse can be transmitted at that point of the neuron (intervals to frequency of action potentials)