Chemical Constituents of Cells
	Protoplasm of cells contains water (the major component of all body fluids), electrolytes, O2, CO2, and macromolecules.    Extracellular fluid - fluid outside the cells including interstitial fluid (tissue fluid) and blood, together with other specific fluids such as urine and cerebrospinal fluid. The extracellular fluid is a part of the extracellular matrix (ECM).    Intracellular fluid - the fluid inside cells, also known as the cytosol.