Informative Essay - Blood Donation

Red blood cells deliver oxygen to the body tissues and remove carbon dioxide from the lungs. Platelets clot the blood clot, and are cell fragments about ¼ the size of a whole red blood cell. Plasma contains proteins to help fight infection. It also brings nutrients to tissues and transports waste to the lungs, liver and kidneys for filtration. Plasma can help patients with liver disease, cancer, and more. Harold Sanford donates blood every week. Each unit of plasma is roughly equivalent to a small bottled drink. His 1000 donations total 500 liters of plasma. It takes around 130 plasma donations to manufacture enough therapy to keep one patient with primary immunodeficiency healthy for one year. When platelets are donated they must be used within five days and red blood cells must be used within 42 days. Plasma and cryoprecipitate is put into a frozen state and can be used up to a year after collected. .
             There are eight common types of blood, which are determined by the presence or absence of certain antigens – substances that can trigger an immune response if they are foreign to the body. There are four major blood groups determined by the presence or absence of two antigens – A and B – on the surface of red blood cell:Group A has only the A antigen on red cells (and B antibody in the plasma). Group B has only the B antigen on red cells (and A antibody in the plasma). Group AB has both A and B antigens on red cells (but neither A nor B antibody in the plasma). Group O has neither A nor B antigens on red cells (but both A and B antibody are in the plasma). There are very specific ways in which blood types must be matched for a safe transfusion. AB can only be donated to blood type AB, B can be donated to B and AB, A can be donated to A and AB, and O can be donated to all blood types. In platelets and plasma, the transfusions are the opposite of red blood cell transfusions.