Permeability of which of the following ion leads to resting membrane potential?
High-Yield Explanation
Ans. B PotassiumRef: Ganotig, 22nd ed. BRS Physiology, 4th ed. pg. 11Ionic Basis of Nerve Resting Membrane Potential* RMP: Resting membrane potential is potential difference across the cell membrane in millivolts, which is by convention -70mV.* RMP is established by diffusion potential that results from concentration differences of permeable ions.* Resting membrane potential (-70mV) is close to equilibrium potential of K+ and Cl- (both -85mV) and far from the equilibrium potential of Na+ (+65mV). That means at rest the nerve membrane is more permeable to K+ than Na+* Na+ is actively transported out of neurons and other cells and K+ is actively transported into cells, but because K+ permeability at rest is greater than Na+ permeability, K+ channels maintain the resting membrane potential.