We define as Intracellular compartment (also known as Intracellular fluid) the liquid part of the cytoplasm (cytosol) where all organelles are embedded. Intracellular compartment is separated by the extracellular fluid, composed of the Plasma and the Interstitial fluid, by the plasma membrane (lipid bilayer) and retains osmotic equilibrium and chemical disequilibrium with the ECF (extracellular fluid). The osmotic equilibrium is achieved at 300mOsm approximately and if disturbed, movement of water from a region of higher concentration to an area of low concentration (downhill transport) occurs thus resulting to either shrink or burst of the cell in extreme cases.
Intracellular compartment accounts for 67% of the total body fluids (approximately 25 Liters) and has high concentrations of K+ and proteins which have multiple responsibilities inside the cell.
- ↑ 1. Alberts B., Johnson A., Lewis J., Morgan D., Raff M., Roberts K., Walter P. Molecular Biology of the Cell. 6th ed., New York, NY: Garland Science, Taylor and Francis