Reducing the extracellular Na+ concentration from a normal value of 150 mM to 75 mM would have what effect on the action potential?
reduce the maximum voltage of the action potential
prevent repolarization of the action potential
prevent the after-hyperpolarization of the action potential
None of the above options are correct.
Reducing the extracellular Na+ concentration from 150 mM to 75 mM would actually have no significant effect on the action potential. The action potential is primarily driven by the movement of ions across the cell membrane, particularly Na+ and K+. While changes in the extracellular Na+ concentration can affect the resting membrane potential, reducing it from 150 mM to 75 mM would still allow for normal depolarization and repolarization during the action potential.