L4 WBCs-1 PDF

# BLOOD PHYSIOLOGY ## L4: LEUKOCYTES **Dr.ABDULRHMAN MUSTAFA** MB,BS -MSc-MHPE, MHAE FAIMER FELLOWSHIP Crt ## OBJECTIVES The student should able to: - Recognize the different types of WBCs. - Identify the normal values of the WBCs - Discuss the functions of each WBC - Distinguish the changes in...

# BLOOD PHYSIOLOGY ## L4: LEUKOCYTES **Dr.ABDULRHMAN MUSTAFA** MB,BS -MSc-MHPE, MHAE FAIMER FELLOWSHIP Crt ## OBJECTIVES The student should able to: - Recognize the different types of WBCs. - Identify the normal values of the WBCs - Discuss the functions of each WBC - Distinguish the changes in WBCs in different clinical conditions ## Classifications of leukocytes - **Granulocytes** - Polymorph-nuclear leukocytes (PMNs) - Neutrophils - Eosinophils - Basophils - **A granulocytes** - Mononuclear leukocytes - Lymphocytes - T lymphocyte - B lymphocyte - Monocytes -> macrophage system A table showing the different types of leukocytes with a diagram outlining their relative sizes and locations in the blood. - **Neutrophil** - **Eosinophil** - **Basophil** - **Lymphocyte** - **Monocyte** ## Normal Counts: | Cell | Approximate Normal range (/μL) | Percentage of Total WBC | |-----------------|---------------------------------|--------------------------| | Total WBC | 4000-11000 | --- | | Granulocytes | --- | --- | | Neutrophils | 3000-6000 | 50-70% | | Eosinophils | 150-300 | 1-4/% | | Basophils | 0-100 | 0.25/0.5% | | Lymphocytes | 1500-4000 | 20-40 | | Monocytes | 300-600 | 2-8 | ## Site of Formation: - Ultimately originate from same undifferentiated stem cells in red bone marrow. - Granulocytes and monocytes are produced only in bone marrow. - Most new lymphocytes are actually produced by lymphocytes already in lymphoid tissues such as lymph nodes and tonsils. - Total number of white cells and percentage of each type may vary considerably to meet changing defense needs. A diagram outlining the process of formation of different blood cells from stem cells in the red bone marrow. ## Leukocytes ### Life span of leukocytes: - Granulocytes: 4-8 hours - Monocytes: 10-20 hours - Lymphocytes & macrophages months & years ## NEUTROPHILS - Most Abundant WBCs 60-70% - Size: 15-20 μm - Nucleus: Multilobed 2-5 lobes - Life span: 6-8 hours - Function is phagcytosis - ACT AGINST BACTRIAL INFECTION **Neutrophils are represented in a diagram of blood cells, exhibiting their multi-lobed nucleus and phagocytosisi ability.** ## DEFENSIVE PROPERTIES of MACROPHAGES & NEUTROPHILS 1. **Diapedesis** (Movement of blood cells to the surrounding tissues) 2. **Chemotaxis** (Cells direct their movement to certain chemicals in their environment) 3. **Opsonization** (A process by which a pathogen is marked for ingestion and destruction) 4. **Degranulation** (secretion of a toxic molecules from the granules) 5. **Phagocytosis & Digestion** (engulfing and destruction of a pathogen) **A diagram shows the process of diapedesis with leukocytes moving through blood vessel walls**, the movement of leukocytes toward a chemotactic source and the pathway of phagocytosis & digestion. ## EOSINOPHIL - Granules contain arginine rich protein, which take acid dye (eosin). - **Functions** - Chemotaxis: attracted towards chronic inflammation. - Neutralizes allergic products such histamine, 5-HT, Ag-Ab complex, bradykinin (allergic disease of skin &lungs) - Phagocytosis is same as neutrophil, but less efficient. - High eosinophil count is seen in parasitic, allergic and dermatological diseases - ACT AGINST PARASITIC INFECTION **A diagram shows eosinophils with their distinctive red cytoplasmic granules** ## BASOPHIL - Granules contain polysaccharide granules base methylene blue color. - Similar to mast cells releases its granules containing heparin, histamine, 5HT. Which causes inflammation reaction - Weak phagocytic cells **A diagram shows basophils with their distinctive purple cytoplasmic granules** ## POLYMORPHNUCLEAR Leukocytes- AntimicROBIAL System ### ENZYMATIC - Heparin - Histamine - Bradykinin - Serotinin - Lysosomal enzymes - Slow reacting substance of anaphylaxis ### NON ENZYMATIC - Respiratory burst (rapid release of reactive oxygen species). - O2 Free Radicals (O-2, H2O2, -ОН). - CI- HoCl Hypochlorous acid "very toxic". ## Monocytes - No Granules but vacoules. - Size: 15-20 μm. - Function: phagocytosis more efficient than Neutrophils. - Life span: 10-20 hours in blood. **A diagram shows monocytes with their amoeboid shape and centrally located kidney-shaped nucleus** ## MONOCYte S ### Reticuloendothelial System: Monocyte/Macrophage System: Consist of: 1. Monocytes. 2. Mobile macrophages. 3. fixed tissue macrophages. 4. specialized endothelial cells in bone marrow, spleen and lymph nodes. ### Examples of Tissue macrophages: 1. Tissue macrophages in skin and subcutaneous tissues (Histiocytes). 2. Macrophages of lymph nodes. 3. Alveolar macrophages. 4. Tissue macrophages in liver sinuses (Kupffer Cells). 5. Macrophages of spleen and bone marrow 6. Microglia in brain. ## LYMPHOCYTES - Provide immune defense against targets for which they are specifically programmed. - Live about 100 to 300 days. - 2 types of lymphocytes - B lymphocytes - Produce antibodies which circulate in blood. - Responsible for antibody-mediated or humoral immunity. - T lymphocytes - Directly destroy specific target cells by releasing chemicals that punch holes in the victim cell (cell-mediated immunity). **A diagram shows lymphocytes with their round, condensed nucleus** ## IMPORTANT terms - Leukocytosis – Increase in WBC count - Leukopenia - Decrease in WBC count - Neutrophilia - Increase in neutrophil count - Leukemias – Abnormal Increase in immature WBC count (blood cancer). - Formation of Pus: - Dead Neutrophils - Dead Macrophages - Necrotic tissue **A diagram shows pus formation at the point of bacterial infection, highlighting the presence of dead leukocytes** ## Samare - **Neutrophils** - Highly mobile phagocytes that engulf and destroy unwanted materials - **Eosinophils** - Secrete chemicals that fight parasites - Involved in allergic reactions - **Basophils** - Release histamine and heparin - Involved in allergic reactions - **Monocytes** - Transformed into macrophages (tissue-bound phagocytic specialists) - **Lymphocytes** - B lymphocytes (ẞ cells) - Transformed into plasma cells that secrete antibodies - T lymphocytes (T cells) - Responsible for cell-mediated immunity ## TABLE 14.4 | Abnormal White Blood Cell Numbers | White Blood Cell Population Change | Illness | |----------------------------------|----------------------------------------------------------------------------| | Elevated lymphocytes | Hairy cell leukemia, whooping cough, mononucleosis | | Elevated eosinophils | Tapeworm infestation, hookworm infestation, allergic reactions | | Elevated monocytes | Typhoid fever, malaria, tuberculosis | | Elevated neutrophils | Bacterial infections | | Too few helper T cells (lymphocytes) | AIDS | ## TABLE 14.5 | Cellular Components of Blood | Component | Description | Number Present | Function | |------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------|-----------------------------------------------------------------------------------| | Red blood cell (erythrocyte) | Biconcave disc without a nucleus, about one-third hemoglobin | 4,200,000 to 6,200,000 per microliter | Transports oxygen and carbon dioxide | | White blood cell (leukocyte) | | 4,500 to 10,000 per microliter | Destroys pathogenic microorganisms and parasites and removes worn cells | | Granulocytes | About twice the size of red blood cells; cytoplasmic granules are present | | | | Neutrophil | Nucleus with two to five lobes; cytoplasmic granules stain light purple in combined acid and base stains | 54%-62% of white blood cells present | Phagocytizes small particles | | Eosinophil | Nucleus bilobed; cytoplasmic granules stain red in acid stain | 1%-3% of white blood cells present | Kills parasites and moderates allergic reactions | | Basophil | Nucleus lobed; cytoplasmic granules stain blue in basic stain | Less than 1% of white blood cells present | Releases heparin and histamine | | Agranulocytes | Cytoplasmic granules are absent | | | | Monocyte | Two to three times larger than a red blood cell; nuclear shape varies from spherical to lobed | 3%-9% of white blood cells present | Phagocytizes large particles | | Lymphocyte | Only slightly larger than a red blood cell; its nucleus nearly fills cell | 25%-33% of white blood cells present | Provides immunity | | Platelet (thrombocyte) | Cytoplasmic fragment | 130,000 to 360,000 per microliter | Helps control blood loss from broken vessels | ## References - Human physiology by Lauralee Sherwood, 9th edition - Text Book Of Physiology by Guyton & Hall, 12th edition - Review of Medical Physiology by Ganong, 24th edition **A diagram of the three textbooks mentioned is shown below.**