Chapter 11 The Blood 335 Copyright Goodheart-Willcox Co., Inc. or hair color, blood type is inherited. Figure 11.12 provides a list of possible blood types that a person may have based on the blood types of his or her parents. The presence of antigen A on the red blood cell indicates type A blood, antigen B indicates type B blood, and the presence of both antigen A and B indicates type AB blood. Some people have neither antigen A nor B on their red blood cells. These people have type O blood. Blood types tend to vary among ethnic groups and regions of the world. Type O is the most common in the United States, and type AB is the rarest (Figure 11.13). Antigens and Antibodies Antigens are large, complex molecules, such as proteins and glycolipids, on the surface of red blood cells. E veryone’s blood contains some similar elements: red blood cells, white blood cells, and platelets. However, not all blood is the same. Several typing systems are used to differentiate among the various types of blood. ABO Blood Grouping System In the ABO blood typing system, there are four distinct types of blood: A, B, AB, and O. Reagents can be used to detect the differences in a process known as blood typing. ABO blood typing was made possible by the groundbreaking work of Karl Landsteiner, an Austrian scientist who won the Nobel Prize for his discovery. Do you know your blood type? Have you ever wondered what determines your blood type? Like eye formed elements the solid components of blood includes red blood cells, white blood cells, and platelets hematocrit the percentage of total blood volume that is composed of red blood cells hematopoietic cells the cells that are responsible for creating blood cells hemoglobin an essential molecule of the red blood cell that serves as the binding site for oxygen and carbon dioxide composed of globin and heme hemolysis the rupture of red blood cells hemostasis the sequence of events that causes a blood clot to form and bleeding to stop hypoxia a condition of having too little oxygen in the blood leukocytes white blood cells mesenchymal cells stromal cells that can develop into tissues of the circulatory and lymphatic systems as well as connective tissues phagocytosis the process by which macrophages in the liver and spleen envelop, digest, and recycle old RBCs and other types of cells plasma the liquid component of blood platelet plug a gathering of platelets that forms a small mass at the site of an injury platelets cell fragments that play a vital role in blood clotting also known as thrombocytes prothrombin a protein in the blood that is activated to form thrombin during clot formation prothrombin activator (PTA) a protein that activates the protein fibrinogen red blood cells blood cells that contain hemoglobin, a protein responsible for oxygen and carbon dioxide transport also known as erythrocytes thrombocytes platelets white blood cells blood cells that fight infection and protect the body through various mechanisms also known as leukocytes Review Questions 1. List at least six functions of blood, two in each of the three major categories described in this section. 2. A centrifuge is used to separate the elements of blood into three layers. Describe the components of each layer. 3. Name at least four physical properties of blood. 4. Where are blood cells manufactured? 5. What does hematocrit measure? List the normal ranges for males and females. 6. Compare and contrast the different functions of red blood cells, white blood cells, and platelets. 7. Explain the blood clotting process. SECTION 11.2 Blood Types Objectives · Describe the ABO blood grouping system. · Explain the Rh classification system and why it is important. Key Terms agglutination antibody antigen erythroblastosis fetalis Rh factor RhoGAM universal donor universal recipient Ch11.indd 335 4/29/2019 11:21:41 AM