(Select all correct answers; one or more than one answer may becorrect.) In cases of renal failure, plasma (extracellular)concentrations of K+ may increase from normal levels of4-5 mM to 10 to 12 mM. From what you know of the effects ofincreasing extracellular K+ on the membrane potential(EK = RT/zF x ln[Ko/Ki) and theeffects of membrane potential on the HCN channel (hint, rememberwhat H stands for), you would expect the increased extracellularconcentration of K+ to:
Group of answer choices:
decrease the rate of rise of the ramp potential for thepacemaker action potential.
decrease cardiac output.
hyperpolarize the membrane potential.
increase the rate of rise of the ramp potential for thepacemaker action potential.
decrease heart rate.
depolarize the resting membrane potential in the pacemakercells.
