Learning Objective

• Use of blood and blood components

When blood has been lost by hemorrhage or during accidents, whole blood is required for replacement. In some disease conditions and in emergency situations, the administration of a single component in concentrated form results in a far better response than the administration of that component as whole blood. By using specific parts of the blood, the supply of blood can be used more economically.

The red cells are used for the treatment of anemia, albumin for the treatment of shock, immunoglobulin for the prophylaxis of certain infectious diseases, and granulocytes for the treatment of granulocytopenia. The plasma present in the blood act as a vehicle for the transport of most nutrients and drugs. Electrolytes and many small organic compounds found in the plasma are freely exchanged with both the lymph and the intestinal fluids. Some of the plasma proteins are involved in the clotting of blood. The erythrocytes present in the blood are involved in oxygen and carbon dioxide transport. Leukocytes play a major role in the defense against microbes and protect the body against infection. Platelets exert a variety of important functions in hemostasis and in response to injury.