2. Blood Physiology 1432 Lecture 3 Leucocytes 1 Professor A M Abdel Gader MD, PhD, FRCP (Lond., Edin), FRSH (London) Professor of Physiology, College of Medicine & the Blood Bank, King Khalid University Hospital King Saud University Riyadh

4. Leucocytes White Blood Cells (WBCs)

5. Objectives of Lecture -3 At the end of this lecture the student should be able to: 1.Describe the different types of WBCs 2.Recognize the general functions of WBCs 3.Describe the genesis and site of formation of WBCs 4.Describe the stages of neutrophil formation 5.Describe the role of the neutrophil in defending the body against infections 6.Describe the process of phagocytosis

6. Leucocytes (WBCs) Contents General Characteristics & types of WBCs Genesis (Production) of WBCs Life Span of WBCs Defense properties of neutrophils & macrophages –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis – Structure and function of Eosinophils and basophils

7. General Characteristics & types of WBCs Genesis (Production) of WBCs Life Span of WBCs Defense properties of neutrophils & macrophages –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis – Structure and function of Eosinophils and basophils Leucocytes (WBCs) Contents

8. Blood Film

10. Hematopoiesis

11. Formed Elements of Blood Red blood cells ( erythrocytes ) White blood cells ( leukocytes ) –granular leukocytes neutrophils eosinophils basophils –agranular leukocytes lymphocytes = T cells, B cells, and natural killer cells monocytes Platelets

12. Leucocytes (WBCs) – cont. General Characteristics & types of WBCs Types of WBC 1.Granular (polymorphnuclear): Neutrophil 62%. –10-16um, nucleus 2-5 lobes, purple cytoplasmic granules Eosinophil 2.3%. –12-18um, 2 lobes nucleus, coarse red granules Basophil 0.4%. –10-14um, rarely segmented nucleus, nucleus hidden by large round bluish granules

13. Leucocytes (WBCs) – cont. General Characteristics & types of WBCs Types of WBC 2.Agranular WBC –Monocytes 5.3% 15-20um, kidney shape nucleus –Lymphocyte 30% round nucleus –small (5-8um) –large (9-15um)

16. General Characteristics & types of WBCs Genesis (Production) of WBCs Life Span of WBCs Defense properties of neutrophils & macrophages –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis Leucocytes (WBCs)- cont. Contents

17. General Characteristics & types of WBCs Genesis (Production) of WBCs Life Span of WBCs Defense properties of neutrophils & macrophages –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis Leucocytes (WBCs)- cont. Contents

18. Leucocytes (WBCs) – cont. Genesis (Production) of WBCs Pluripotential stem cell Committed Stem cell RBCs WBCs Platelets MylocyticLymphocytic Linage

19. Figure 16-5c: Bone marrow

20. Hematopoiesis

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22. Leucocytes (WBCs) – cont. Genesis (Production) of WBCs- leucopoiesis) Sites of WBC formation Granulocytes (neutrophil, basophil, eosinophil): –bone marrow Agranulocytes –lymphocytes- bone marrow, thymus, lymphoid tissues –monocytes- bone marrow

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24. General Characteristics & types of WBCs Genesis (Production) of WBCs Life Span of WBCs Defense properties of neutrophils & macrophages –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis Leucocytes (WBCs)- cont. Contents

25. General Characteristics & types of WBCs Genesis (Production) of WBCs Life Span of WBCs Defense properties of neutrophils & macrophages –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis Leucocytes (WBCs)- cont. Contents

26. Life Span of WBCs Granulocytes: 4 to 8 hrs (transit time ) in blood circulation 4 to 5 hrs in tissues –In infections life span a few hours Monocytes : –10 to 20 hrs in blood circulation –Leave capillaries to tissues, increase in size to become tissue macrphages which live for months

27. Life Span of WBCs- cont. Lymphocytes: A few hrs in blood circulation >> tissues >> lymph >>> Blood (Recirculation) ?Life span: weeks to months

28. General Characteristics & types of WBCs Genesis (Production) of WBCs Life Span of WBCs Defense properties of neutrophils & macrophages –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis Leucocytes (WBCs)- cont. Contents

29. General Characteristics & types of WBCs Genesis (Production) of WBCs Life Span of WBCs Defense properties of neutrophils (& macrophages) –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis Leucocytes (WBCs)- cont. Contents

30. Leucocytes (WBCs) General Characteristics & types of WBCs Genesis (Production) of WBCs Life Span of WBCs Defense properties of neutrophils & macrophages –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis

31. Defense properties of neutrophils (& macrophages) Attack and destroy bacteria, viruses Sequence of events: –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis

33. Netrophils function-cont. Defense properties of neutrophils & macrophages- cont Phyagocytosis: Engulfing and killing of bacteria or any invading organism Steps: Chemotaxis: –Bacterial & viral toxins Products of damaged tissues : attract neutrophil to accumulate at infected site. –Opsonization: plasma substances (IgG) attached to the bacteria to make them easy to phagocyte

34. Diapedesis

35. http://www.whfreeman.com/immunology/CH01/diapedesis.htm

36. Defense properties of neutrophils & macrophages Attack and destroy bacteria, viruses Sequence of events: –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis

38. Defense properties of neutrophils & macrophages Attack and destroy bacteria, viruses Sequence of events: –Chemotaxis –Diapedesis –Amaeboid Motion –Phagocytosis

39. Phagocytosis- cont. Phagocytosis is selective: Distinguish self from non-self…... How? –Normal tissues have smooth surface –Normal tissues have protective protein surface –Antibodies coating bacteria ( Opsonization)

40. Phagocytosis

41. Microbial killing 41

42. Phagocytosis by neutrophils- cont. Neutrophils attach to bacteria & encircled it with pseudopodia and take it into a vacuole (phagosome). One Neutrophil can engulf 3 to 20 bacteria One Macrophage can engulf up to 100 bacteria Microbial killing: fusion of neutrophil granules with vacuole, –Discharge of lysozyme, myeloperoxidase enzymes into the vacuole, killing and digesting the engulfed bacteria. –Release of Free radicals by oxidizing agents: superoxide, hydrogen peroxide to kill the bacteria

44. Leucocytes (WBCs) – cont. Types of WBC 1.Granular (polymorphnuclear): Neutrophil 62%. –10-16um, nucleus 2-5 lobes, purple cytoplasmic granules Eosinophil 2.3%. –12-18um, 2 lobes nucleus, coarse red granules Basophil.4%. –10-14um, rarely segmented nucleus, nucleus hidden by large round bluish granules

45. Blood Film

46. Eosinophils Function: Phagocytosis: Phagocytosis is same as neutrophil, but less efficient Chemotaxis: eosinophil attracted towards chronic inflammation/allergic tissue ( allergic disease of skin & lungs) By eosinophil chemotactic factor Phagocytose (& detoxify) antigen/antibody complexes

47. Eosinophils cont, High eosinophil count: –Parasitic (hook worm, ascaris, bilharzia) –Allergic (asthma, rhinitis, drug reaction) –Allergic skin diseases

48. Leucocytes (WBCs) – cont. Types of WBC 1.Granular (polymorphnuclear): Neutrophil 62%. –10-16um, nucleus 2-5 lobes, purple cytoplasmic granules Eosinophil 2.3%. –12-18um, 2 lobes nucleus, coarse red granules Basophil.4%. –10-14um, rarely segmented nucleus, nucleus hidden by large round bluish granules

49. Leucocytes (WBCs) – cont. Types of WBC 1.Granular (polymorphnuclear): Neutrophil 62%. –10-16um, nucleus 2-5 lobes, purple cytoplasmic granules Eosinophil 2.3%. –12-18um, 2 lobes nucleus, coarse red granules Basophil.4%. –10-14um, rarely segmented nucleus, nucleus hidden by large round bluish granules

50. Blood Film

51. Basophils Similar to tissue mast cells Non-phagocytic cells Granules: dark blue color. Granules contain: –Heparin –Histamine –Serotonin (5HT). Released during allergic reactions

52. Objectives of Lecture -3 At the end of this lecture the student should be able to: 1.Describe the different types of WBCs 2.Recognize the general functions of WBCs 3.Describe the genesis and site of formation of WBCs 4.Describe the stages of neutrophil formation 5.Describe the role of the neutrophil in defending the body against infections 6.Describe the process of phagocytosis

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