Dr.N.N.Kumari 6 October MBBS-year-1,Term-1 MCBM 1 Element-2 Lec-15 Leucocytes

2Dr.N.N.Kumari 6 October 2011 Leukocytes 1.Morphology of various types of WBC as seen in a stained blood smear 2.An overview of functions of leukocytes 3.Normal total leukocyte count 4.Differential leukocyte count 5.Common causes of leukocytosis and leukopenia 6.Physiologic significance of leukocytosis Distinction between leukocytosis and leukemia. 7.An overview of leukopoiesis

3Dr.N.N.Kumari 6 October 2011 Classification of leucocytes 1.Based on the presence of granules in the cyotplasm Granulocytes Cytoplasm contains granules, Nucleus if lobed Agranulocytes No granules in the cytoplasm, Single nucleus 2.Based on staining property of granules NeutrophilsEosinophilsBasophils MonocyteLymphocytes SmallLarge

4Dr.N.N.Kumari 6 October 2011 Total Leucocyte count: Total number of WBC in 1 cmm. of blood Normal range 4000 – 11000/cmm of blood Differential leukocyte count: Percentage of each type of WBC

5Dr.N.N.Kumari 6 October 2011 CellAverageCell/µl Normal Range % of total WBC Total WBC Granulocytes Neutrophil Eosinophil Basophil Lymphocytes Monocytes Normal value for the leucocytes

6Dr.N.N.Kumari 6 October 2011 Morphology of leucocytes RBC 7.2 µ Platelet Peripheral blood smear showing three types of blood cells stained with Leishman’s stain Polymorphonuclear leucocytes Neutrophil Size: Size: µ Nucleus:2-5 lobes Granules: Fine, violet colour, numerous.

7Dr.N.N.Kumari 6 October 2011 Eosinophil : Size:10-14µ Bilobed nucleus Granules: Coarse, reddish pink, less number Granules contain active substances involved in inflammatory and allergic reactions Morphology of leucocytes-2Basophil: Size:10-12 Size:10-12µ, 2 lobed nucleus lightly stained Granules: Big,deep blue, very few.

8Dr.N.N.Kumari 6 October µ Large Lymphocyte µ Single kidney shaped Sky blue large amount Small Lymphocyte 8µ Large nucleus, small amount of cytoplasm Immunity 14-18µ Monocyte µ Horse shoe shaped nucleus Greyish blue rarely fine granules are seen Phagocytosis

9Dr.N.N.Kumari 6 October 2011 Variation in cell count 1.Neutrophilia :Inc. in neutrophil count All conditions that are mentioned under leucocytosis Neutropenia : Dec. in neutrophil count All conditions that are mentioned under Leucopenia 2.Eosinophilia : Inc in eosinophil count Asthma, urticaria, anaphylaxis, parasitic infestations, (hookworm, ascaris, filaria) Skin diseases eczema scabies psoriasis Eosinopenia : Dec.in eosinophil count. ACTH injection, Cushing’s syndrome.

10Dr.N.N.Kumari 6 October 2011 Variation in cell count-2 Lyphocytosis: increase in lymphocyte count Infants during Convalescence from acute infection In whooping cough Chronic infections like tuberculosis, syphilis Viral infections like measles, mumps, chikenpox Monocytosis: Increase in monocytes * Glandular fever * Tuberculosis * Malaria * Syphilis * Bacterial endocarditis

11Dr.N.N.Kumari 6 October 2011 Leucocytosis Increase in total WBC count Leucocytopenia Decrease in total WBC count New born ( /µl) Typhoid, Paratyphoid fever Muscular exercise, asphyxia Malaria, influenza EmotionsExcitement Acute bacterial infections Appendicitis, empyema Pneumonia, Postoperative patients Bone marrow depression due to chloramphenicol, Cephalosporin sulphona- mides, X-rays, Radiation Severe septic conditions of throat

12Dr.N.N.Kumari 6 October 2011 Functions Of leucocytes Neutrophil & monocytes : Phagocytosis Lymphoctes: Immunity Eosinophil: Eosinophils kill juvenile parasites SchistosomiasisTrichinella Detoxify inflammation inducing substances Destroy allergen antibody complexes Basophil: antigen antibody reaction  rupture of basophil & mast cell  Release heparin, histamine, bradykinin, serotonin cause local vascular and tissue reactions  many of the allergic manifestations

13Dr.N.N.Kumari 6 October 2011 Physiologic significance of leukocytosis Leucocytosis : increase in Total WBC count usually due to Increase in neutrophils It is confirmed by Differential leucocyte count. Eg acute infections tonsillitis acute appendicitis 15,000-40,000/cmm with 80-90% neutrophils

14Dr.N.N.Kumari 6 October 2011 LeucocytosisLeukaemia Increase in WBC count 11,000-50,000/cmm 50, ,000/cmm Normal cells Presence of immature blast cells Exercise,pregnancy Acute infections: localized / generalized e.g. tonsillitis appendicitis pneumonia Non infectious :myocardial infarction burns, surgical operations, acute hemorrhage Myeloid leukaemia (Cancerous growth of myeloid tissue) or lymphoid tissue (lymphoid leukaemia

15Dr.N.N.Kumari 6 October 2011 Movement of neutrophils by Diapedesis through capillary pores and by Chemotaxis toward an area of tissue damage

16Dr.N.N.Kumari 6 October Margination : Neutrophils & monocytes get attached to endothelium after bacterial invasion 2.Diapedesis 3.Ameboid motion 4.Chemotaxis 5.Opsonization :microorganisms are coated with IgG make it tasty to the phagocytes 6.Phagocytosis-Formation of Phagosome- Phagocytic vesicle 7.Fusion of Phagosome with lysosome  8.Digestive vesicle 9.Digestion of bacteria by bactericidal agents proteolytic enzymes 10.Discharge of waste products. Steps in phagocytosis

17Dr.N.N.Kumari 6 October 2011 Neutrophils, Monocytes/Macrophages defend against infections by phagocytosis Tissue macrophage is first line of defense against infections Neutrophil invasion of the inflamed area is a second line of defense.

18Dr.N.N.Kumari 6 October 2011 Phases of phagocytosis

19Dr.N.N.Kumari 6 October 2011 Leucopoiesis: Formation and maturation of WBC In fetal life: Mesoderm cells. Post natal life: Granulocytes & Monocytes develop from the red bone marrow( myeloid) Lymphocytes from lymphoid tissues All blood cells are made from a relatively few 'uncommitted' cells which are capable of mitosis and of differentiation into 'committed' precursors of each of the main types of blood cell.

20Dr.N.N.Kumari 6 October 2011 Hematopoiesis in humans

21Dr.N.N.Kumari 6 October 2011 GranulopoiesisMonocytopoiesis

22Dr.N.N.Kumari 6 October 2011 Lymphopoiesis

23Dr.N.N.Kumari 6 October 2011 until Granulocyte & monocytes are formed only in the bone marrow-stored in the bone marrow until they are needed. Life span Granulocytes- 4-8 hrs in circulating blood 4-5 days in tissues Monocytes hrs in blood As tissue macrophage several months Lymphocytes- weeks or months Lymphocytes & Plasma cells are formed in lymphogenous tissues-lymph glands, spleen, thymus, tonsils & Payers patches in the intestines

24Dr.N.N.Kumari 6 October 2011 Bone marrow Granulocytes Monocytes/macrophages Regulation of leucopoiesis Acute inflammation  colony stimulating factors Granulocyte colony stimulating factor (GCSF) Macrophage colony stimulating factor (MCSF) Granulocyte macrophage (GM-CSF)

25Dr.N.N.Kumari 6 October 2011 Factors Necessary for White Blood Cell Formation a. Aminoacids b. Folic acid Vitamin B 12 & other B group vitamins c. Products of neutrophil destruction (nucleic acids) d. Colony stimulating factors (CSF) e. Interleukins d & e factors cause growth and differentiation of the stem cells, progenitor cells and precursor cells.