336 Anatomy & Physiology Essentials Copyright Goodheart-Willcox Co., Inc. this technology were grim. In the fledgling days of medicine, physicians did not know about the different blood types. Some transfusions were successful due in large part to luck, but others resulted in serious complications or death. When a person with type A blood is transfused with blood from a type B blood donor, the recipient’s anti-B antibodies bind to the donor’s red blood cells. This causes the donated red blood cells to clump together in a process called agglutination. Agglutination creates blockages in smaller blood vessels and is potentially fatal. Agglutination also causes hemolysis, or destruction, of the donated red blood cells. Hemolysis releases hemoglobin into the bloodstream. Hemoglobin may accumulate in the kidneys, causing kidney damage and failure, or even death. Blood transfusion reactions can also be milder, with symptoms ranging from fever and chills to vomiting. Regardless, it is extremely important that blood types be classified and matched before transfusion. SELF CHECK 1. What determines a person’s blood type? 2. Name the four blood types in the ABO blood grouping system. 3. Which blood type classifies someone as a universal recipient? a universal donor? They identify cells as “self” or “nonself,” making it possible for the body to tell the difference between its own cells and foreign cells. The presence of foreign cells causes the immune system to produce antibodies that mark the foreign cells for destruction. Antibodies circulate in plasma and bind to any cells that have antigens different from those found in the host’s blood (or blood recipient during a transfusion). Chapter 13 describes antigens and antibodies in more detail. Figure 11.14 shows the antigens and antibodies associated with each blood type. People with AB blood have A and B antigens on their RBCs, but neither A nor B antibodies in their plasma, making them a universal recipient. A universal recipient can safely receive blood of any type. People with type A blood have RBCs with only A antigens on their RBCs and B antibodies in their plasma, and those with type B blood have only B antigens on their RBCs and A antibodies in their plasma. People with type O blood have neither A nor B antigens on their red blood cells, but both A and B antibodies in their plasma. Because type O blood has no antigens, anyone can receive type O blood. Thus, people with type O blood are universal donors. Blood Transfusions Understanding blood types is critical for blood transfusions and surgery. The history of blood transfusions shows that the earliest outcomes of Inherited Blood Type Parent 1 AB AB AB AB B A A O O O Parent 2 AB B A O B B A B A O Possible blood type of child O X X X X X X A X X X X X X X B X X X X X X X AB X X X X Figure 11.12 Goodheart-Willcox Publisher Blood Type by Ethnicity Prevalence (% of US Population) Blood Group Caucasian African-American Hispanic Asian Native American AB 3 4 2 5 1 B 9 20 10 27 4 A 41 27 31 28 16 O 47 49 57 40 79 Figure 11.13 Goodheart-Willcox Publisher