fluid compartments
Last reviewed 01/2018
Fluid compartments
- intracellular fluid, ICF - two thirds - 28 litres
- extracellular fluid, ECF - one third - 14 litres
- of which
- 80% interstitial
- 20% plasma - 2.8 litres
ICF contains principally K, proteins, organic ions. ECF contains principally Na, Cl, HCO3. Plasma contains principally albumin, HCO3, Cl, Na.
Division by membranes:
- ICF - membrane - ECF - membrane - PLASMA
- membrane between ICF and ECF
- cellular membrane permeable to water - Osmotic gradient
- membrane between ECF and plasma
- capillary membrane permeable to water and electrolytes - pressure gradient