After studying this chapter you will be able to: Describe the components of blood, giving the function of each component listed; explain how bleeding is controlled; explain the differences among blood types A, B, AB, and O, including in the discussion which blood types are compatible;...
CHAPTER 27 The Blood 27-2 Learning Outcomes (cont.) 27.1 Describe the components of blood, function of each component listed 27.2 giving the Explain how bleeding is controlled 27.3 Explain the differences among blood types A, B, AB, and O; including in the discussion which blood types are compatible 27-3 Learning Outcomes (cont.) 27.4 Explain the difference between Rhblood and Rh-negative blood positive 27.5 Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the blood 27-4 Introduction • Blood – 4-6 liters per adult ~ 8% of body weight – Essential functions • Carries oxygen and nutrients • Removes carbon dioxide and wastes • Transport mechanism for hormones • Regulation of body temperature 27-5 Components of Blood • Red blood cells – erythrocytes – Small biconcaveshaped cells – Small enough to pass through capillaries 27-6 Blood Components (cont.) • Hematocrit – The percentage of red blood cells – Normally about 45% • White cells and platelets = 1% • Plasma = 55% 27-7 Blood Components (cont.) • Hemoglobin – Oxyhemoglobin carries oxygen – Deoxyhemoglobin ~ carries carbon dioxide • RBC count – Normally between million and 6.5 million RBC/ml – Anemia 27-8 Blood Components (cont.) • RBCs – Produced in the red bone marrow – Life span ~ 120 days – Erythropoietin • Produced by kidneys • Stimulates bone marrow • Released when oxygen concentrations are low 27-9 Blood Components (cont.) • RBC production – Iron – Vitamin B12 – Folic acid • Aging RBCs – Destroyed by macrophages in liver and spleen – Biliverdin released and converted to bilirubin by the liver 27-10 White Blood Cells • Leukocytes - WBCs – Granulocytes • Neutrophils – 55% • Eosinophils – 3% • Basophils – < 1% 27-25 Blood Types (cont.) Blood Type Antigen on RBC Antibody in Plasma Blood That Can Be Received A A B A and O B B A B and O AB A and B None A, B, AB, and O O None A and B O 27-26 Apply Your Knowledge Identify the blood type: ANSWER: 27-27 Rh Factor • Rh antigen – Rh-positive – Rh-negative • Transfused blood – Match for Rh factor – 1st unmatched transfusion ~ antibodies develop – 2nd time ~ agglutination 27-28 Rh Factor • Erythroblastosis fetalis – Mother developed antibodies to the Rh antigen in prior pregnancy – Antibodies attack fetus’ blood – Infant ~ severe anemia 27-29 Rh Factor (cont.) 27-30 Apply Your Knowledge What is the difference between Rh-positive and Rh-negative blood and why is it important to know whether a person is RH-positive or negative before transfusing blood? ANSWER: Rh-positive blood contains the Rh antigen while Rh-negative blood does not If a person with Rhnegative blood receives a transfusion of Rh-positive blood, he will develop antibodies to the Rh antigen If he receives any subsequent transfusions of Rhpositive, agglutination will occur Bravo! 27-31 Diseases and Disorders of the Blood System Disease Description Anemia The blood does not have enough RBCs or hemoglobin to carry an adequate amount of oxygen to the body’s cells Leukemia Bone marrow produces a large number of abnormal WBCs Sickle cell anemia Abnormal hemoglobin causes RBCs to change to a sickle shape; abnormal cells stick in capillaries 27-32 Diseases and Disorders of the Blood System (cont.) Disease Description Polycythemia vera Disease of the bone marrow that results in an abnormally high number of blood cells, especially RBCs, causing the blood to thicken Thalassemia Inherited form of anemia; defective hemoglobin chain causes, small, pale, and short-lived RBCs 27-33 Apply Your Knowledge The doctor has told your patient she has anemia How would you explain this to her? ANSWER: Anemia is a condition in which a person does not have enough red blood cells or hemoglobin in the blood to carry an adequate amount of oxygen to body cells Way to go! 27-34 In Summary 27.1 The formed elements in blood include: red blood cells that are responsible for oxygen and carbon dioxide transport; white blood cells that are responsible for working with the immune system by fighting infection; and platelets, which assist in blood clotting The liquid component of blood is called plasma and when all clotting factors and formed elements are spun out of plasma, the remaining liquid is called serum 27-35 In Summary (cont.) 27.2 Hemostasis refers to the control of bleeding Three basic processes occur during hemostasis: blood vessel spasm; platelet plug formation; and blood coagulation Clot formation is coagulation It involves fibrinogen converting to fibrin, which sticks to the damaged area of the blood vessel, creating a meshwork that entraps blood cells and platelets 27-36 In Summary (cont.) 27.3 The four blood types are: A, B, AB and O The antibodies attached to each type (except AB, which has no antibodies) require that each blood type receive only its specific antigen type during transfusions So, A receives A or O; B receives B or O; AB as the universal receiver can receive any blood type; and O, although the universal donor, may receive only type O blood 27-37 In Summary (cont.) 27.4 Rh factor is an antigen that may be attached to any blood type Its importance arises during transfusions (Rhnegative blood cannot receive Rh-positive blood) and also during pregnancy if the mother is Rhnegative but the fetus received the Rh-positive antigen from the father The effect on the first fetus will be little, but unless treated, any subsequent Rh-positive fetus will suffer effects of erythroblastosis fetalis, as the mother’s blood developed antibodies against the Rh-positive factor during the initial pregnancy 27-38 In Summary (cont.) 27.5 There are many different types of blood diseases described within this chapter The signs, symptoms, and treatments are as varied as the diseases themselves The Common Diseases and Disorders for the Blood System section of this chapter outlines the most common of these diseases, their signs and symptoms, as well as their treatments 27-39 End of Chapter 27 The bond that links your true family is not one of blood, but of respect and joy in each other’s life ~ Richard Bach ... AB, and O; including in the discussion which blood types are compatible 27- 3 Learning Outcomes (cont.) 27. 4 Explain the difference between Rhblood and Rh-negative blood positive 27. 5 Describe the. .. bleeding First the blood vessel spasms, then a platelet plug forms, and lastly, the blood coagulates forming a blood clot 27- 23 ABO Blood Types • Blood types are distinguished by antigens and antibodies... That Can Be Received A A B A and O B B A B and O AB A and B None A, B, AB, and O O None A and B O 27- 26 Apply Your Knowledge Identify the blood type: ANSWER: 27- 27 Rh Factor • Rh antigen – Rh-positive