Resting membrane potential in ventricular myocardium: (A) -50mV, (B) >70mV, (C) +70mV, (D) -90mV
Answer is D. Ventricular cardiomyocyte membrane potential is about -90 mV at rest, which is close to the potassium reversal potential. When an action potential is generated, the membrane potential rises above this level in four distinct phases.