90 MV more negative inside fiber than in extracellular fluid - na+-k+ pump influences both ion concentrations & electropotential.
Leakage: channel protein exist in nerve membrane which k+ and na+ can leak, emphasis on k+ because 100 times more permeable to k+ - if k+ is the only ion to move through the membrane, the resting potential inside fiber would equal -94 mv (1:35 inner/outer ratio). Slight permeability of na+ through leak channels + nernst potential of +61 mv (10:1 inner/outer ratio), brings resting potential to -86 mv (ghk) - na+/k+ pump creates additional -4 mv, bringing resting potential to -90 mv.
