Water is a solvent.
The composition of solutes in intracellular and extracellular water is different. Intracellular contains high amounts of potassium. Extracellular contains sodium and chloride. After ingestion of water, it leaves the large intestine and eventually flows into 1 of the body's fluid compartments. Blood vessel walls act as a barrier between the plasma and interstitial fluid and permit the flow of all constituents except protein.