In cases of renal failure, plasma (extracellular) concentrationsof K+ may increase from normal levels of 4-5 mM. From what you knowof the effects of increasing extracellular K+ on the membranepotential and the effects of membrane potential on the HCN channel,you would expect the increased extracellular concentration of K+to:
a. decrease heart rate
b. decrease cardiac output
c. depolarize the resting membrane potential in the pacemakercells
d. all of the above are correct
e. only a and b are correct
