White Blood Cell 1 PDF

The White Blood Cell 1 Dr. Harini Narayanam Department of Physiology, Faculty of Medicine Learning Outcomes At the end of this chapter, the student should be able to 1. Describe the morphology of the various types of leucocytes, their normal count and mention the site of formation. 2. Describe...

The White Blood Cell 1 Dr. Harini Narayanam Department of Physiology, Faculty of Medicine Learning Outcomes At the end of this chapter, the student should be able to 1. Describe the morphology of the various types of leucocytes, their normal count and mention the site of formation. 2. Describe the functions of various types of WBCs. 2 The White Blood Cell The white blood cells (WBCs) or leucocytes granule in These are nucleated cells and play cytoplasm an important role in the defense mechanism of the body The leucocytes of the peripheral blood are of two main varieties including granulocytes and agranulocytes 3 Types of White Blood Cell Neutrophil Granulocytes Eosinophil Leucocytes Basophil D B-lymphocytes Monocyte T-lymphocytes Functional Agranulocytes Natural killer cell Lymphocytes Small lymphocyte Morphological Large lymphocyte 4  Types of White Blood Cell Leucocytes Granulocytes Agranulocytes The white blood cells with White blood cells which do not granules in their cytoplasm contain granules in their cytoplasm Neutrophils Eosinophils Basophils Lymphocytes Monocytes They contain granules They contain They contain which take both granules which granules which acidic & basic stain. take acidic stain take basic stain Fine granule Course :.. thinchromain a granule... · i 5 · - Trilobed nucleus bilobed nucleus /2 nucleus cytoplasm WBCs Formation = Leucopioesis The monophyletic theory pluripotent or multipotent stem cell. A series divisions differentiate into progenitor cells which are also called colony forming units (CFU) WBCs 6 WBCs Differentiation Erythroid progenitors Erythrocytes (RBCs) Megakaryocyte Myeloid Platelets progenitors Granulocyte-monocyte Pluripotent Neutrophil progenitors Stem cell Eosinophil Can give rise to any type of blood cells. Lymphoid Lymphocytes Basophil Monocytes 7 Total Leucocytes Count Adults At birth Infant – 1 year 4000 – 10,000 – 6,000 – 11,000 / µL 25,000 / µL 16,000 / µL of blood of blood of blood 8 Normal Count & Variations to reaction. philia Respond allergy penia t - Do Not Let Monkey Eat Banana 9 Morphology of WBCs (Granulocytes) to form bone store 12 days - in marrow Cell Type Size Nucleus Cytoplasm Life span 10-14μm Neutrophils Pale bluish with 50%-70% 1-5 lobes violet-pink 2-5 days granules 10-14μm Eosinophils Bilobed or spectacle Eosinophillic, brick 1%-4% shaped red, coarse 7-12 days numerous granules 10-14μm Few, thick, bluish or Basophils Irregular bilobed & violet granules, 0.4% masked by thick partially masking the 12-15 days bluish granules nucleus, cell border is not clear 10 Morphology of WBCs (Agranulocytes) Cell Type Size Nucleus Cytoplasm Life span Small 8-10μm Single lobe, Little cytoplasm, lymphocytes condensed and usually crescentic 20%-40% appears like a large shaped, basophillic, ink spot sky blue, no granules 12-16μm Large, single lobe Abundant less than Up to 1 day Large condensed nucleus, basophillic, lymphocytes chromatin centrally sky blue in colour, placed darkly stained no granules 15-20μm Large, single lobe Abundant cytoplasm nucleus, kidney more than nucleus, Monocytes shaped or round, fine basophilic, grey blue 2%-8% chromatin reticulum or light blue, no 2-5 days lightly stained granules in cytoplasm 11 Functions of WBCs WBCs provides powerful defences against tumours and viral, bacterial, and parasitic infections. Neutrophils destroy microorganisms by phagocytosis and are considered as the first line of defence against infection. Eosinophils are antiallergic and antiparasitic in function. ❖They provide local immunity in GIT, respiratory & urinary tracts. ❖They destroy parasites by releasing hydrolytic enzymes. Basophils secrete heparin & histamine. ❖Heparin is an anticoagulant. ❖Histamine produces allergic reactions. 12 Functions of WBCs (Cont.) Monocytes are phagocytic in nature, they enter the tissues and become tissue macrophages. e.g. ❖ Kupffer cells of the liver. ❖ Pulmonary alveolar macrophages. ❖ Microglia in the brain. Lymphocytes are involved in immunity and protect against specific pathogens. ❖ B lymphocytes are concerned with humoral immunity. ❖ T lymphocytes are concerned with cell mediated immunity. 13 Practice SAQ 1. Describe the structure of different types of leucocytes? 2. State their normal count? 3. Discuss functions of various types of WBCs? 4. Write short note on different abnormal clinical condition arise due abnormal count of WBC? 14 15 The White Blood Cell 2 Dr. Harini Narayanam Department of Physiology, Faculty of Medicine Learning Outcomes At the end of this chapter, the student should be able to 1. Define immunity and mention various types of immunity. 2. Describe the role of lymphocytes in immunity. 3. Discuss the differences between the humoral and cellular immunity. 2 Overview of Immunity Our environment is rich in varieties Organisms enter the body they multiply, and of infectious microbes, such as if their growth and multiplication are bacteria, viruses, fungi, protozoa unchecked, they produce disease in the host and multicellular parasites and eventually they may even kill the host. Immunity Definition The process of defense of the body against harmful elements that threaten our normal health 3 Classification of Immunity Immunity / Immune Immune responses broadly Response involve two steps: 1. Recognition of pathogen or the foreign material 2. Reactions or responses to Innate immunity Acquired immunity eliminate it. The responses (non-adaptive) (adaptive) are called immune responses 4 Classification of Immunity Immunity / Immune Response Innate immunity Acquired immunity (non-adaptive) (adaptive) Nonspecific Relatively specific Naturally Artificially defenses defense by NK cells acquired acquired Active immunity Passive immunity Active immunity Passive immunity Vaccination I.V injection Cellular Humoral Ig G via Ig A via of Ab immunity immunity placenta breast feeding 5 Innate Immunity (Non-specific Defense) Non-specific defence systems include the skin and mucous membrane (mechanical factors and chemical factors), antimicrobial mechanisms (interferons and complements), natural killer cells, phagocytosis, inflammation and fever Defense by Chemical phagocytic defense cells Defense by Mechanical Defense by inflammation defense NK cells & fever Granulocytes Acidic pH of Skin, (neutrophils, eosinophil Bactericidal Substance and basophil), monocytes of Sebum, Acidic pH of and macrophages kill Systemic Response to Skin, mucous, hair, Lymphocytes micro-organisms by Stomach, Complement Inflammation, cilia, tear, saliva, skin neither B nor T phagocytosis Proteins & Interferon Inflammatory Cells & cells & defaecation Cytokines 6 Role of Granulocytes & Mononuclear Cells Granulocytes (neutrophils, eosinophil and basophil), monocytes and macrophages kill micro-organisms by phagocytosis 7 Role of Neutrophil in Phagocytosis Margination: Neutrophil movement towards the wall of capillary in the area of infection Diapedesis: Squeezing through pores in capillary wall and entering the tissue Chemotaxis: Attraction to the site of inflammation by chemicals released at the site of infection by various cells Opsonization: Complement factors + antibodies gets attached to bacteria. Endocytosis Degranulation Exocytosis 8 Roles of Lymphocytes in Immunity ❖ B lymphocytes are concerned with humoral immunity: B cells binds to an antigen → differentiate into plasma cells → secrete antibodies (immunoglobulins) → attack & neutralize antigens. Major defence against bacterial infections ❖ T lymphocytes are concerned with cellular immunity: T cells activated by antigen presenting cells → activated T cells release cytotoxic substances → destroy the cells with the antigen Major defence against viral or fungal infections & tumors. 9 Adaptive Immunity Humoral Immunity: due to the Cellular Immunity: due to the presence of presence of antibodies in the body: cytotoxic T cells in the body: Antibodies are formed by plasma These cells develop and proliferate in cells. Plasma cells are developed response to a particular antigen and kill from activated B cells in response to that organism antigen. This immunity is particularly effective This immunity works mainly against against intracellular organisms like extracellular organisms such as viruses, parasites and fungi, cancer bacteria and the antigens dissolved cells, tumor cells, and transplanted in the body fluids. tissues. 10 Adaptive Immunity General outline of the development of immunity. T4 cells induce development of both cellular and humoral immunity. 11 Components of Humoral Immunity B lymphocytes that produce circulating antibodies in the globulin fraction of the plasma proteins (immunoglobulin) 12 Steps in Humoral Immunity 1. Presentation of antigen 2. Activation of B cells 3. Differentiation of B cells into plasma cells 4. Proliferation of plasma cells and antibody production 5. Killing of the invaders by antibodies that include activation of complement system 6. Formation of memory B cells and subsequent immunological responses 13 Mechanism of Humoral Immunity cell Helper T > - 14 Components of Cellular Immunity 1. Helper T Cells (T4 Cells) ❖ The helper T cells are called T4 cells as they contain CD4 protein on their cell surface. 2. Cytotoxic T Cells ❖ These are called T8 cells as they contain CD8 protein on their cell membrane. 3. Memory T Cells ❖ A small subset of T cells remains in the tissue as memory T cells. 15 Steps in Cellular Immunity 1. Antigen recognition, processing and presentation 2. Activation and proliferation of T cells 3. Elimination of the invader 16 Mechanism of Cellular Immunity 17 Humoral Immunity vs Cellular Immunity Humoral Immunity Cell Mediated Immunity Humoral immunity refers to a components Cell mediated immunity refers to the other of the adaptive immunity where B calls component of the adaptive immunity which secrete antibodies – circulate in the blood mediated by activated, antigen specific T as a soluble protein cell Mediated by B cell Mediated by T cells Acts on extracellular microbes and their Acts on intracellular microbes such as toxins viruses, bacteria, parasite and tumor cells B cell secrete antibodies T cell secrete cytokines Rapid immunity A delay type hypersensitivity immunity Does not act on the tumor cell and Acts on tumor cells and transplants transplants 18 Practice SAQ 1. Describe the components of innate immunity. 2. Explain the role of B-lymphocytes in immunity. 3. Briefly mention the process of cell mediated immunity 4. Distinguish between the innate and adaptive immunity. 5. Differentiate between cell mediated and humoral immunity. 19  Credits/Disclaimer PPT Courtesy Dr Kamarulzaman The figures ,animations etc used in the presentation are not my own. They are taken from textbooks and internet. 20 21