Intracellular vs extracellular ion concentrations Lon 工 intracellular Extracellular 5-15mM 145mM K 140mM 5 mM Mg2+ 0.5mM 1-2mM ca 10-7mM 1-2mM H 1072M(pH72)10-74M(pH74 C 5-15mM 110mM13 Intracellular vs extracellular ion concentrations Ion Intracellular Extracellular Na+ 5-15 mM 145 mM K + 140 mM 5 mM Mg2+ 0.5 mM 1-2 mM Ca2+ 10-7 mM 1-2 mM H+ 10-7.2 M (pH 7.2) 10-7.4 M (pH 7.4) Cl- 5-15 mM 110 mM