1. Chapter 19, part 1
Blood

2. Learning Objectives
List the components of the cardiovascular system and explain the major functions of this system.
Describe the important components and major functions of the blood
List the characteristics and functions of red blood cells.
Describe the structure of hemoglobin and indicate its functions.
Discuss red blood cell production and maturation.

3. Learning Objectives
Explain the importance of blood typing and the basis for ABO and Rh incompatibilities.
Categorize the various white blood cells on the basis of structure and function.
Describe the structure, function and production of platelets.
Describe the reaction sequences responsible for blood clotting.

4. SECTION 19-1 The Cardiovascular System: An Introduction

5. The cardiovascular system
Provides a mechanism for rapid transport of nutrients, waste products, respiratory gases and cells

6. SECTION 19-2 Functions and Composition of Blood

7. Blood Fluid connective tissue Functions include
Transporting dissolved gases, nutrients, hormones, and metabolic wastes
Regulating pH and ion composition of interstitial fluids
Restricting fluid loss at injury sites
Defending the body against toxins and pathogens
Regulating body temperature by absorbing and redistributing heat

8. The composition of blood
Plasma and formed elements comprise whole blood
Red blood cells (RBC)
White blood cells (WBC)
Platelets
Can fractionate whole blood for analytical or clinical purposes

9. Figure 19.1 The Composition of Whole Blood
Figure 19.1a

10. Figure 19.1 The Composition of Whole Blood
Figure 19.1b

11. Figure 19.1 The Composition of Whole Blood
Figure 19.1c

12. Hemopoiesis Process of blood cell formation
Hemocytoblasts are circulating stem cells that divide to form all types of blood cells
Whole blood from anywhere in the body has roughly the same temperature, pH and viscosity

13. SECTION 19-3 Plasma

14. Plasma Accounts for 46-63% of blood volume 92% of plasma is water
Higher concentration of dissolved oxygen and dissolved proteins than interstitial fluid

15. Plasma proteins more than 90% are synthesized in the liver Albumins
60% of plasma proteins
Responsible for viscosity and osmotic pressure of blood

16. Additional Plasma Proteins
Globulins
~35% of plasma proteins
Include immunoglobins which attack foreign proteins and pathogens
Include transport globulins which bind ions, hormones and other compounds
Fibrinogen
Converted to fibrin during clotting
Removal of fibrinogen leaves serum

17. SECTION 19-4 Red Blood Cells

18. Abundance of RBCs
Erythrocytes account for slightly less than half the blood volume, and 99.9% of the formed elements
Hematocrit measures the percentage of whole blood occupied by formed elements
Commonly referred to as the volume of packed red cells

19. Structure of RBCs
Biconcave disc, providing a large surface to volume ration
Shape allows RBCs to stack, bend and flex
RBCs lack organelles
Typically degenerate in about 120 days.

20. Figure 19.2 The Anatomy of Red Blood Cells

21. Hemoglobin
Molecules of hemoglobin account for 95% of the proteins in RBCs
Hemoglobin is a globular protein, formed from two pairs of polypeptide subunits
Each subunit contains a molecule of heme which reversibly binds an oxygen molecule
Damaged or dead RBCs are recycled by phagocytes

22. Figure 19.3 The Structure of Hemoglobin

23. Figure 19.4 “Sickling” in Red Blood Cells

24. RBC life span and circulation
Replaced at a rate of approximately 3 million new blood cells entering the circulation per second.
Replaced before they hemolyze
Components of hemoglobin individually recycled
Heme stripped of iron and converted to biliverdin, then bilirubin
Iron is recycled by being stored in phagocytes, or transported throughout the blood stream bound to transferrin

25. Figure 19.5 Red Blood Cell Turnover

26. RBC Production Erythropoeisis = the formation of new red blood cells
Occurs in red bone marrow
Process speeds up with in the presence of EPO (Erythropoeisis stimulating hormone)
RBCs pass through reticulocyte and erythroblast stages

27. Figure 19.6 Stages of RBC Maturation

28. 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

29. Figure 19.8 Blood Typing and Cross-Reactions

30. Figure 19.9 Blood Type Testing

31. Figure 19.10 Rh Factors and Pregnancy

32. SECTION 19-5 The White Blood Cells

33. 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

34. 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

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

36. Figure 19.11 White Blood Cells

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

38. 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

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

40. SECTION 19-6 Platelets

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

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

43. 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

44. SECTION 19-7 Hemostasis

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

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

47. Figure 19.13 The Vascular and Platelet Phases of Hemostasis

48. 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

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

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

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

52. 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

53. 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.

54. 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.