If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________.
A) threshold is reached more quickly and heart rate would increase
B) potassium channels compensate and no change in heart rate would occur
C) heart rate would decrease, but blood pressure would rise due to the excess sodium present
D) tetanic contraction would occur due to the short absolute refractory period of cardiac muscle

Question

Quizplus · Accepted Answer

If the membrane permeability of pacemaker cells is artificially altered to allow more rapid sodium influx, threshold will be reached more quickly and the speed of depolarization will increase, resulting in an increase in heart rate.

If We Were Able to Artificially Alter the Membrane Permeability