Plasma is the blood’s liquid component, which not only carries the blood cells suspended within it (blood’s cellular component), but also serves as a transport system delivering various materials to and from cells.
Plasma is actually a yellow, straw-like color and, while mostly composed of water, contains other components such as proteins, salts, lipids and glucose.
Plasma retrieves the materials necessary for the body’s survival from such organs as the liver and the small intestine. These materials, delivered to the cells, are usually the results of digestion: amino acids, glucose, mineral salts, vitamins, lipids, hormones and ions.
Plasma is also essential to the body’s defense, as it contains antibodies, antitoxins,and fibrin, a clotting agent that works with the platelets to heal wounds.
Along with vital elements, plasma carries harmful substances such as urea from the cells to the kidney, where it is excreted in urine. It also absorbs the carbon dioxide resulting from respiration as hydrogen carbonate ions, which returns to carbon dioxide when the body exhales.
Plasma can be donated via a process called Plasmapheresis, in which a machine removes the plasma from the donor’s blood and returns the white blood cells, red blood cells and platelets.
Donated plasma can be used as an immunoglobulin to help treat immune disease, to help coagulation in bleeding disorders like hemophilia, to treat respiratory conditions, and to help the healing process in surgery and in treating serious wounds.
Blood plasma is not to be confused with the physical state of matter called plasma, which is ionized gas and electrons that typically make up stars. It is the fourth state of matter (in addition to liquid, solid, and gas) and actually the most common of the four.