(physioex 9 exercise 3)

This is the question I am asked. What is meant by resting membrane potential? What is meant by resting membrane potential? What are the charges and ion concentrations on the inner and outer surfaces of the membrane?

Does this sound okay?


Resting membrane potential is the voltage “charge” difference across the cell membrane when the cell is at rest. Na+ & K+ pump keeps a higher concentration of sodium on the outside of a cell compared to the potassium on the inside of the cell. Ion leak channels allow K+ to follow outward, but they don’t allow Na+ ions to flow inwards. The inside of a typical cell has a concentration of K+ of ~150mM and the concentration of Na+ of ~5 mM. The typical outer cell concentration of K+ is ~5 mM and the concentration of Na+ is ~150 mM. Large negative anions are essentially trapped within the cell and are not excreted contributing to the cell interior's negative potential. The average RMP is around -70mV.