Physiology The action potential of the sinoatrial node A Reuslts from the activation of rapid Na+ channels B Results from opening of the slow Ca2+ channels C Is equivalent in height and conduction velocity to that of the atrial muscle D Results from an increase in conductance to K+ 💡 Explanation The action potential of the sinoatrial node ✓ Correct Answer: B. Results from opening of the slow Ca2+ channels