Intracellular fluid composition
The intracellular fluid consists of small molecules of water, inorganic ions, medium molecules of lipids, amino acids, nucleotides, large molecules of proteins, nucleic acids, lipoproteins, and polysaccharides. The ionic composition is very different from the extracellular fluid. The cations in the intracellular fluid are mainly K +, which accounts for more than 90% of the total cations in the intracellular fluid. There are also a small amount of sodium ions and magnesium ions. Rarely. These ions play an important role in maintaining the stability of the intracellular fluid osmotic pressure and electrical neutrality. Among them, HPO42-, H2PO4- and proteins play an important role in maintaining the stability of intracellular fluid pH.