Dentistry Blood PDF

Dr. Shehab Hafez Level (1) Dentistry General Histology (BMS122) The Blood Prof. Dr. Shehab Hafez Professor of Histology & Cell Biology Mansoura University  Dr. Shehab Hafez Contents of blood Blood cells...

Dr. Shehab Hafez Level (1) Dentistry General Histology (BMS122) The Blood Prof. Dr. Shehab Hafez Professor of Histology & Cell Biology Mansoura University  Dr. Shehab Hafez Contents of blood Blood cells Blood plasma 1. RBCs (Erythrocytes). 2. WBCs (Leucocytes). 3. Blood platelets.  Dr. Shehab Hafez RBCs (Erythrocytes) Normal shape of RBCs ▪ In stained blood smear: biconcave discs ▪ Transmission EM: classic with pale center. This shape provides a dumbbell shape (DB). 20% to 30% greater surface area.  Dr. Shehab Hafez Abnormal shape of RBCs Size (diameter) of RBCs Spherocytosis (biconvex) ▪ Normal size: 6-9 µm. ▪ Macrocytic anemia: ˃ 9 µm. ▪ Microcytic anemia: ˂ 6 µm. Number of RBCs Normal number ▪ In males: 5-5.5 million/mm³ ▪ In females: 4.5-5 million /mm³ Sickle-shaped Anemia ▪ A concentration of RBCs below the normal range. Polycythemia ▪ A concentration of RBCs above the normal range.  Dr. Shehab Hafez Structure of RBCs The erythrocyte is highly adapted for its principal function of oxygen and carbon dioxide transport. ▪ Flexible cell membrane: This flexibility → easy change in shape of RBCs → easy passage through capillaries. ▪ No nucleus or cell organelles. ▪ The RBC contains: Hemoglobin molecules. Enzymes of anaerobic glucose metabolism (source of energy). ▪ Life span of RBC: (120 days): worn out RBCs are destroyed by macrophages of spleen & bone marrow.  Dr. Shehab Hafez WBCs (Leucocytes) ▪ Normal number: 4,000-11,000/ mm³ ▪ Abnormal number: Leucocytosis: ˃11000 Leucopenia: ˂4000 Classification of Leucocytes A. Granular Leucocytes B. Non- Granular Leucocytes ▪ Neutrophils ▪ Lymphocytes ▪ Eosinophils ▪ Monocytes ▪ Basophils Depending on the presence or absence of specific granules  Dr. Shehab Hafez Neutrophils ▪ Percentage: 60-75% of total WBCs. ▪ Size: 10-15 µm. ▪ Nucleus: multilobed (2-5 segments). ▪ Cytoplasm: Specific granules: bactericidal & bacteriostatic substances. Non- specific granules: lysosomes. Functions Defense against acute infection by microorganisms: ▪ They phagocytose the microorganism. ▪ Both specific & non-specific granules kill & digest the organism. Neutrophilia ▪ Increase the number above 75%. ▪ In acute bacterial infections e.g. tonsilitis.  Dr. Shehab Hafez Eosinophils ▪ Percentage: 2-5% of total WBCs. ▪ Size: 10-15 µm. ▪ Nucleus: Bilobed (horseshoe-shaped). ▪ Cytoplasm: Large acidophilic granules. ▪ Functions: the granules have: Anti-allergic action Antiparasitic action (e.g. anti- Bilharziasis). Eosinophilia ▪ Increase the number above 5%. ▪ In allergic conditions & parasitic diseases.  Dr. Shehab Hafez Basophils ▪ Percentage: less than 1% of total WBCs. ▪ Size: 10-15 µm. ▪ Nucleus: Large and irregular. ▪ Cytoplasm: Large basophilic granules: similar to the granules of mast cells: contain heparin & histamine. Functions ▪ Supplement the function of mast cells in immediate hypersensitivity reaction  Dr. Shehab Hafez Lymphocytes ▪ Percentage: 20-30% of total WBCs. ▪ Size: variable: Small: 4 µm……Large: 10-12 µm. ▪ Nucleus: dark with condensed chromatin. ▪ Cytoplasm: little: contains non-specific granules only. Types 1. B- lymphocytes ▪ Mature in Bone marrow. ▪ Responsible for humoral immunity. 2. T-lymphocytes ▪ Mature in the Thymus gland. ▪ Responsible for cell-mediated immunity. 3. Natural killer cells  Dr. Shehab Hafez Monocytes ▪ Percentage: 3-8% of total WBCs. ▪ Size: 12-20 µm. The largest WBC. ▪ Nucleus: large and kidney-shaped. ▪ Cytoplasm: Abundant and contains numerous non-specific granules. ▪ Function: Gives origin of macrophages.  Dr. Shehab Hafez Blood platelets ▪ Rounded or oval discs. ▪ Number: 150,000-400,000/mm³ ▪ Size: 2-4 µm. ▪ No Nucleus. The cytoplasm 1. Outer pale part (hyalomere): ▪ Microtubules & microfilaments; to maintain the shape of the platelet. 2. Inner granular part (granulomere): Alpha granules; fibrinogen & other proteins important for blood clotting. Delta (δ) granules: serotonin, ATP, ADP & calcium ions. Lysosomes, Mitochondria & glycogen granules. H: hyalomere G: granulomere  Dr. Shehab Hafez Resources ▪ Junqueira LC, Carneiro J: Junqueira’s Basic Histology. Text and Atlas, thirteenth edition (2013), LANGE Mc Graw Hill. ▪ Gartner LP and Hiatt JL: Color Textbook of Histology. Third edition (2007). Saunders Elsevier. Prof. Dr. Shehab Hafez