Item #10 of 10

The backflow of an action potential in the direction of initiation is prevented by ___________.

the efflux of potassium at the Node of Ranvier;
a decrease in the threshold of excitation at the Node of Ranvier;
a shift in the threshold of excitation underneath the myelin sheath;
the influx of sodium underneath the myelin sheath;
none of the alternatives is correct;

INCORRECT - A decrease in the threshold would increase the chances of triggering an action potential, no matter where it occurred.

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