membraan evenwichts-potentiaal

Aangezien PCl ≈ 0 geldt:

          R T        PK [K+]o + PNa [Na+]o
Em = ─── ln ──────────────
           F          PK [K+]i + PNa [Na+]i

met PK : PNa ≈ 1 : 0.04

                         1 [K+]o + 0.04 [Na+]o
Em = 0.026 ln ──────────────
                         1 [K+]i + 0.04 [Na+]i

of

                         1 × 5 + 0.04 × 145
Em = 0.026 ln ────────────
                         1 × 140 + 0.04 × 10

                         10.8
Em = 0.026 ln ────
                         140.4

Em = 0.026 ln (−2.6) ≈ −70 mV