Extracellular (plasma) concentration
= 140 mmol/L
Intracellular concentration
= 10 mmol/L
Interstitial concentration
= 140 mmol/L
NB:
[KB2:p13]
Interstitial concentration of protein is lower than plasma concentration
According to Gibbs-Donnan equilibrium
--> Sodium concentration in ISF should be lower
In fact, this is the case
--> Sodium concentration in the plasma water (i.e. without proteins) is about 6 or 7 mmol/L higher than ISF
--> But overall concentration is roughly the same
[KB2:p14]
Total body Na+
= 60mmol/kg
NB:
NB:
Also see Daily balance of sodium and water