Chapter 19, part 2

1. Chapter 19, part 2 Blood

2. Blood types • Determined by the presence or absence of surface antigens (agglutinogens) • Antigens A, B and Rh (D) • Antibodies in the plasma (agglutinins) • Cross-reactions occur when antigens meet antibodies

3. Figure 19.8 Blood Typing and Cross-Reactions Figure 19.8

4. Figure 19.9 Blood Type Testing Figure 19.9

5. Figure 19.10 Rh Factors and Pregnancy Figure 19.10

6. SECTION 19-5The White Blood Cells

7. Leukocytes • Have nuclei and other organelles • Defend the body against pathogens • Remove toxins, wastes, and abnormal or damaged cells • Are capable of amoeboid movement (margination) and positive chemotaxis • Some are capable of phagocytosis

8. Types of WBC • Granular leukocytes • Neutrophils – 50 to 70 % total WBC population • Eosinophils – phagocytes attracted to foreign compounds that have reacted with antibodies • Basophils – migrate to damaged tissue and release histamine and heparin

9. Types of WBC • Agranular leukocytes • Monocytes - become macrophage • Lymphocytes – includes T cells, B cells, and NK cells

10. Figure 19.11 White Blood Cells Figure 19.11

11. Differential count • Indicates a number of disorders • Leukemia = inordinate number of leukocytes

12. WBC Production • Granulocytes and monocytes are produced by bone marrow stem cells • Divide to create progenitor cells • Stem cells may originate in bone marrow and migrate to peripheral tissues • Several colony stimulating factors are involved in regulation and control of production

13. Figure 19.12 The Origins and Differentiation of Formed Elements Animation: The origins and differentiation of blood cells PLAY Figure 19.12

14. SECTION 19-6Platelets

15. Platelets • Flattened discs • Circulate for 9-12 days before being removed by phagocytes

16. Platelet functions • Transporting chemicals important to clotting • Forming temporary patch in walls of damaged blood vessels • Contracting after a clot has formed

17. Platelet production (thrombocytopoiesis) • Megakaryocytes release platelets into circulating blood • Rate of platelet formation is stimulated by thrombopoietin, thrombocyte-stimulating factor, interleukin-6, and Multi-CSF

18. SECTION 19-7Hemostasis

19. Hemostasis • Prevents the loss of blood through vessel walls • Three phases – • Vascular phase • Platelet phase • Coagulation phase

20. Hemostasis • Vascular phase • Local blood vessel constriction (vascular spasm) • Platelet phase • Platelets are activated, aggregate at the site, adhere to the damaged surfaces

21. Figure 19.13 The Vascular and Platelet Phases of Hemostasis Figure 19.13

22. Coagulation phase • Factors released by platelets and endothelial cells interact with clotting factors to form a clot • Extrinsic pathway • Intrinsic pathway • Common pathway • Suspended fibrinogen is converted to large insoluble fibrin fibers

23. Figure 19.14 The Coagulation Phase of Hemostasis Figure 19.14a

24. Figure 19.14 The Coagulation Phase of Hemostasis Figure 19.14b

25. Clot retraction • Final phase of healing • Platelets contract and pull the edges of the vessel together

26. Fibrinolysis • Clot gradually dissolves through action of plasmin • Activated form of plasminogen • Clotting can be prevented through the use of drugs that depress the clotting response or dissolve existing clots • Anticoagulants include heparin, coumadin, aspirin, dicumarol, t- PA, streptokinase, and urokinase

27. You should now be familiar with: • The components of the cardiovascular system and its major functions. • The important components and major functions of the blood. • The characteristics and functions of red blood cells. • The structure of hemoglobin and its functions. • Red blood cell production and maturation.

28. You should now be familiar with: • The importance of blood typing and the basis for ABO and Rh incompatibilities. • The various white blood cells. • The structure, function and production of platelets. • The reaction sequences responsible for blood clotting.