How does hyperkalemia cause excitability of the membrane? I'm looking to understand the mechanisms of K+ and how that affects it. I already know that the RMP becomes more positive, but I am wondering why specifically.

Question

aaronq · Answer

The resting membrane potential is more positive because the potassium-sodium balance is disrupted (more positive charges outside than inside).

anonymous · Answer

Wouldn't that increase the difference in charges between the membrane?

aaronq · Answer

i shouldn't have write the "more positive charges outside" part. I didn't say what i meant.

the potential is more positive because a higher [K+] affects the equilibrium concentrations, so after the system has equilibrated, the [K+] on both sides of the membrane is higher.

anonymous · Answer

Because of the concentration gradient and the constant leakage of the potassium? Would that cause more K+ to go into the cell?

aaronq · Answer

i'm not sure by what process K+ ions would enter the cell, but like any system, raising the conc. of a participant will raise it's concentration throughout.