Osmosis

The passage of a solvent from a weaker solution to a more concentrated one through a semipermeable membrane. All body cells are surrounded by such membranes, which allow water, salts, simple sugars (such as glucose), and amino acids (but not proteins) to pass through. Therefore, osmosis plays an important part in regulating the distribution of water and other substances in body tissues.

 

Online Medical Dictionary: Your essential reference to over 5000 medical terms.