Explain how the body can be in osmotic equilibrium but electrical and chemical disequilibrium

-Osmotic equilibrium occurs because water moves freely between most cells and the extracellular fluid

-Water will continue to move across membranes into more highly concentrated compartments until the concentrations (solute/volume) are equal, hence osmotic equilibrium

-Osmotic equilibrium does not take into account what particles are present in each compartment, just the total number. 

-the key is that water moves freely but the solutes do not.

-Na+ and Cl- are more highly concentrated in the ECF while K+ and many anions are more highly concentrated inside the cell.

-Each ion is in chemical disequilibrium because it is not evenly distributed between the two compartments.

-Although the compartments are chemically different (chemical disequilibrium), when all solutes in one compartment are compared to all the solutes in another compartment they have the same total concentrations of solutes (are in osmotic equilibrium).