The EKG is hooked up, and Mr. M's trace looks very abnormal. His heart rate is low. The T wave, which indicates repolarization of the ventricles, is unusually large and pointed and the QRS wave, which indicates the depolarization impulse’s passage through the ventricles, is widened or slowed. "That's a classic EKG for hyperkalemia (high blood potassium)!" The doctor gives Mr. M an injection of calcium gluconate. Calcium ions block the Na+ channels on nerve and muscle cells. How will this help counteract the effects of high blood K+? g