Physiology

[VerityAnne]

In a normal person, hyperkalemia causes decreased intracellular negativity which means depolarization happens more easily (resting potential is closer to threshold) and it also inhibits repolarization. Why is repolarization inhibited? Are depolarization and repolarization similarly affected by hyperkalemia in people who have channelopathies? I'm specifically working on Na+ channelopathies associated with hyperkalemia. I've read Na+ channels are unable to help regulate K+ potassium levels (because they stay open too long), so they cannot generate action potentials. But it seems if the person has hyperkalemia, it should be easier to generate an AP since depolarization happens more easily. Of course, if repolarization is inhibited it makes sense that an AP could not be generated until the membrane had a chance to repolarize. I've also found information that talks about muscle hyper-excitability due to hyperkalemia with Na+ channelopathies. It seems this would be a product of the depolarization happening more easily. But it also seems this should not be the case if repolarization is inhibited because repolarization would still need to occur before depolarization could happen again, right? Sorry if this seems all over the place. My head feels a bit scattered.