1. Chapter Goals After studying this chapter, students should be able to... 1. describe the composition of blood plasma and the physical characteristics and functions of the formed elements of the blood. 2. identify the chemical regulators of blood cell production and describe the process of erythorpoiesis. 3. describe the ABO system of red blood cell antigens and explain the significance of the blood types. 4. explain how a blood clot is formed and how it is ultimately destroyed.

2. BLOOD Components Immunity Blood Groups

3. Background Centrifuge  2 fractions: plasma & formed elements. Percentage of blood composed of formed elements = hematocrit (normal range = 42 - 45%; too high = polycythemia).

4. 11-1

5. Components Plasma Formed Elements –Erythrocytes –Leucocytes –Thrombocytes

6. Plasma Composition –i. Water –ii.Proteins aa. Fibrinogen - involved in clotting bb. Prothrombin - involved in clotting cc. Albumins - maintain blood osmotic pressure dd. Globulins - mainly antibodies –iii.Salts –iv.Lipids –v.Carbohydrates - glucose

7. Plasma Function –i. Transports materials for cellular metabolism –ii. Transports excretory products –iii. Water balance –iv. Heat regulation –v. Transports hormones

8. Formed Elements Erythrocytes Leucocytes Thrombocytes

9. 11-7

10. 11-8

11. Erythrocytes –anucleate, biconcave discs (=RBCs) Low pO 2 -----> release of erythropoietin ---> erythropoiesis (stem cell = hemocytoblast) Females 4.5 - 5 x 10 6 cells/mm 3 Males 5 - 5.5 x 10 6 cells/mm 3 Lifespan ~ 120 days Contain hemoglobin Lungs O 2 + Hb HbO 2 Tissues

12. Hemoglobin 11-3

13. Erythropoiesis 11-4

14. Hematocrit 11-5

15. Leucocytes Granular (=polymorphonuclear) –Neutrophils –Eosinophils –Basophils Agranular –Lymphocytes –Monocytes

16. Granular Leucocytes Neutrophils (4,500 cells/mm 3 ) - phagocytic. 3-lobed nucleus; equal numbers of red and blue granules. Eosinophils (100 cells/mm 3 ) - increase with allergies and parasitic infections. Two-lobed nucleus; large red granules in cytoplasm Basophils (25 cells/mm 3 ) - may produce heparin. Spiral, U-shaped nucleus; large blue granules in cytoplasm obscure nucleus

17. Agranular Leucocytes Lymphocytes (1,925cells/mm 3 ) - may help produce antibodies Monocytes (450 cells/mm 3 ) - phagocytic. Get to site of infection more slowly than neutrophils, but more resistant to bacterial toxins (~ 100 bacteria engulfed before death vs ~ 5 for neutrophils)

18. Thrombocytes Production 11-9

19. Thrombocytes 11-10

20. Thrombocytes Hemostasis 11-12

21. Clotting Cascade 11-13

22. Thrombocytes Hemostasis 11-14

23. Thrombocytes Prevention of intravascular clots –Endothelial Repulsion –Anticoagulants (e.g. heparin) –Clot dissolution 11-15

24. Blood and Immunity Cellular-mediated Immunity (via phagocytes) a. Phagocytic blood cells (leucocytes) b. Phagocytic cells not in the blood (magrophages) Humoral Immunity (via antibodies)

25. Antibodies 12-11

26. Antibody Formation 12-13

27. Transfusion Reactions 12-16

28. Types of Immunity –i. Natural immunity (innate) - born with maternal antibodies –ii.Active immunity (above) –iii.Cross immunity - one antibody protects against more than one disease (e.g. small pox vs cow pox) –iv. Passive immunity - borrowed (e.g. anti- snake venom serum from immunized horse)

29. Blood Types ABO Blood Groups TypeAntigen AntibodyDonates toReceives from A A  A, AB A, O B B  B, AB B, O ABA & B NONE AB A,B,AB,O ONONE  A,B,AB,O O

30. Blood Types Rh Blood Groups TypeAntigen AntibodyDonates toReceives from Rh+ + none + -, + Rh- none + +,- - –Erythroblastosis fetalis –Note: RhoGam (anti-Rh antibody) destroys fetal RBCs, which have Rh antigens on their surface, before the mother becomes sensitized.

31. Chapter Summary Functions and Components of the Circulatory System I. The blood transports oxygen and nutrients to all the cells of the body and removes waste products from the tissues. It also serves a regulatory function through its transport of hormones. A. Oxygen is carried by red blood cells, or erythrocytes. B. White blood cells, or leukocytes, sever to protect the body from disease. II. The circulatory system consists of the cardiovascular system (heart and blood vessels) and the lymphatic system.

32. Chapter Summary Composition of the Blood I. Plasma is the fluid part of the blood, containing dissolved ions and various organic molecules. A. Hormones are found in the plasma portion of the blood. B. Plasma proteins include albumins; globulins (alpha, beta and gamma); and fibrinogen. II. The formed elements of the blood include erythrocytes, leukocytes, and platelets. A. Erythrocytes, or red blood cells, contain hemoglobin and transport oxygen. B. Leukocytes may be granular (also called polymorphonuclear) or agranular. They function in immunity. C. Platelets or thrombocytes are required for blood clotting. III. The production of red blood cells is stimulated by the hormone erythropoietin, and the development of different kinds of white blood cells is controlled by chemicals called lymphokines.

33. Chapter Summary IV. The major blood typing groups are the ABO system and the Rh system. A. Blood type refers to the kind of antigens found on the surface of the red blood cells. B. When different types of blood are mixed, antibodies against the red blood cell antigens cause the red blood cells to agglutinate. V. When a blood vessel is damaged, platelets adhere to the exposed subendothelial collagen proteins. A. Platelets that stick to collagen undergo a release reaction, in which they secrete ADP, serotonin, and thromboxane A 2. B. Serotonin and thromboxane A 2 cause vasoconstriction. ADP and thromboxane A 2 attract other platelets and make them stick to the growing mass of platelets that are stuck to the collagen in the broken vessel.

34. Chapter Summary VI. In the formation of a blood clot, a soluble protein called fibrinogen is converted into insoluble threads of fibrin. A. This reaction is catalyzed by the enzyme thrombin. B. Thrombin is derived from prothrombin, its inactive precursors, by either an intrinsic or an extrinsic pathway. 1. The intrinsic pathway, the longer of the two, requires the activation of more clotting factors. 2. The shorter extrinsic pathway is initiated by the secretion of tissue thromboplastin. C. The clotting sequence requires Ca 2+ as a cofactor and phospholipids present in the platelet cell membranes. VII. Dissolution of the clot eventually occurs by the action of plasmin, which cleaves fibrin into split products.