Histology 1: Blood and Bone Marrow PDF

Dr/ Shereen Elabd Course Title : Histology 1 Course Code : FM 103 Department : Basic Science Lecture Title : Blood and Bone Marrow Lecturer Name : Shereen Shawky Elabd Assistant professor of Medical Histology and Cell Biology Faculty of Medicine.. Tanta Univ...

Dr/ Shereen Elabd Course Title : Histology 1 Course Code : FM 103 Department : Basic Science Lecture Title : Blood and Bone Marrow Lecturer Name : Shereen Shawky Elabd Assistant professor of Medical Histology and Cell Biology Faculty of Medicine.. Tanta University  Dr/ Shereen Elabd Lecture Objectives: Each student at this lecture should be able to: -Enumerate the blood components. -Enumerate the types of leucocytes. -Discuss the structure and function of erythrocytes, different leucocytes and platelets. -Define the hemopoietic stem cells. -Compare between yellow and redbone marrow. Blood smear Dr/ Shereen Elabd Gimesa stain = Eosin Y + Methylene blue + Azure Leishman stain Blood Dr/ Shereen Elabd Blood is a specialized connective tissue consisting of cells and fluid extracellular material called plasma. Plasma Cells Red Blood cells RBCs White Blood cells WBCs Platelets  Dr/ Shereen Elabd Erythrocytes RBCs Mature Erythrocytes: Shape: Biconcave → increase surface area for gas exchange when adhere together form rouleux shape. Structure: NOT TRUE CELL NO nucleus NO organelles A) Cell membrane: 1- Typical- soft- elastic (allow the passage through small capillaries). 2- The glycoprotein of cell coat has the antigens for ABO system. B) Well developed cytoskeleton. C) Hemoglobin: O2 carrying protein felling the cytoplasm (uniform acidophilia). Function: a- Carry O2 from lung to the cells. b- Carry the CO2 from tissue to the lung.  Dr/ Shereen Elabd Immature Erythrocytes (Reticulocytes): Shape: Spherical Number : 1% of peripheral circulation. Reticulocytes Structure: - Not nucleated increased in - Mitochondria Hemorrhage - Free ribosomes stained with brilliant cresyl blue Hemolysis High altitude forming blue intracytoplasmic precipitate - Filled with hemoglobin. Increase or decrease in reticulocyte count can be an indicator of erythropoiesis activity or failure An increase in erythropoietin (EPO) levels stimulates the bone marrow to increase reticulocyte production. Erythrocytes normally survive in the circulation for about 120 days. By this time, defects in the membrane or cytoskeleton begin to damage. Due to lacking nuclei, RBCs cannot replace the defective proteins. The damaged RBCs are recognized and removed from circulation by macrophages of the spleen.  Dr/ Shereen Elabd Differences between erythrocyte and reticulocyte Erythrocyte Reticulocyte Shape of cell Biconcave Spherical Organelles No Mitochondria Free ribosomes Nucleus Not nucleated Not nucleated Hemoglobin Present Present Brilliant cresyl blue No Blue intracytoplasmic precipitate  Leucocytes Dr/ Shereen Elabd Total leukocytic count: 4-11x103 mm3 True cells (contain nucleus and organelles) Spherical (in plasma) ALL Motile and amoeboid (in connective tissue) Origin in bone marrow and circulate in blood then invade (diapedesis) the connective tissue Types of leukocytes Granular Leukocyte Agranular Leukocyte Non-specific Primary lysosomes containing hydrolytic enzymes granules (Azurophilic granules) Specific Divide according to the stain of the No specific granules granules specific granules Name of cell Neutrophils Eosinophils Basophils Lymphocytes Monocytes Stain and Dye Neither Acidophilic Basophilic ------------ ------------- acidophilic nor (eosin) (methylene basophilic blue)  I- Granular leukocyte Dr/ Shereen Elabd Neutrophil/polymorph Eosinophil Basophil Percentage 50-70% 1-4% 0-0.5% difficult to find in smear Nucleus - Lobulated (2-5) - Bilobed (horse-shoe) - U shaped or S shaped - In : Barr body is attached one lobule. Specific granules - Not acidophilic nor basophilic - Acidophilic - Basophilic & metachromatic (Secondary granules) - Small –numerous - Large- oval - Obscure the nucleus - LM stained faintly pink - Elongated with crystalline - Large - Contain: Collagenase & dense core - Contain: heparin and histamine Bactericidal enzymes - Contain: histaminase & MBP (major basic protein) Azurophilic granules Primary lysosomes contain hydrolases (Non-specific granules) Organelles Golgi complex- RER- Mitochondria- Glycogen Function -The first leukocytes to arrive at -Release histaminase at site - Has IgE receptors. sites of infection. of allergic reaction. - Share with mast cell in allergic -Phagocytosis of bacteria and kill -MBP kill parasites. reaction. them by granules ezymes Increase -Suppurative inflammation Allergy. Allergy As acute suppurative tonsilitis Parasitic infestation Liver cirrhosis  Dr/ Shereen Elabd Neutrophil Eosinophil Basophil Barr Body  Dr/ Shereen Elabd I- Agranular leukocyte Lymphocytes Monocyte Percentage 20-40 % Small Lymphocytes Large Lymphocytes 3-8%The precursor of (Activated) macrophage and other mononuclear phagocytic system Nucleus - Large filling the cell - Larger Kidney shape or C shape - Rounded - Rounded and indented - Dark - Less condensed Cytoplasm - Thin rim of cytoplasm - More cytoplasm - Basophilic cytoplasm - Basophilic - Pseudopodia - Free ribosomes - More azurophilic granules - Few azurophilic granules Lymphocyte Monocyte  Dr/ Shereen Elabd Types of Lymphocytes Lymphocytes are morphologically similar, they are subdivided by distinctive surface molecules (called “cluster of differentiation” or CD markers) that can be distinguished using antibodies with immunocytochemistry. B lymphocyte T Lymphocyte (NK) Natural Killer cell Percentage 15% 80 % 5% Life span - Months - Years Site of Maturation - Bone marrow - Thymus Fate after activation - Plasma cell - T cytotoxic (CD8+ ) - B memory cell - T helper (CD4+ ) - T suppressor - T memory Function - Humoral immunity - Cellular mediate immunity - Kill virus infected cells - Attack tumor cell  Platelets/ Thrombocytes Dr/ Shereen Elabd Origin: Giant bone marrow cell Megakaryocyte with multilobed nucleus Meg Function: promote blood clotting and wound healing. - repair minor tears or leaks in the walls of small blood vessels, preventing loss of blood from the microvasculature. Normal platelet counts range from 150,000 to 400,000/μL (mm3) of blood. Structure: They are non nucleated cytoplasmic fragments surrounded by P cell membrane and glycocalyx. In a blood smear, platelets appear as; aggregates or clumps, each is discoid in shape with a H peripheral lightly stained hyalomere region surrounding a G more darkly stained central granulomere containing membrane-enclosed granules.  Dr/ Shereen Elabd EM Structure: It is divided into 2 regions Outer lighter peripheral zone /Hyalomere Inner darker zone/ Granulomere 1- Marginal bundle: microtubules and microfilaments 1- Mitochondria, peroxisome and glycogen (forming discoid shape) 2- Open canalicular system: 2-Granules: - Vesicles connected to invaginations in plasma membrane → Alpha granule: PDGF, fibrinogen (large) → Delta granule : Dense {ATP, ADP, serotonin} → Lambda granule: lysosome 3- Dense tubular system: - derived from ER - Store Ca+ The two systems facilitate the rapid exocytosis of proteins from platelets (degranulation) upon adhesion to any substrates outside the vascular endothelium.  Dr/ Shereen Elabd Types of bone marrow Red marrow Yellow marrow Activity Active Inactive Site Fetus: all bones Adult: Medullary canal of long bone only Adult: Cavities of spongy bone only Function Formation of blood cells Storage of fat Structure A) Stroma: - Cells A) Stroma - Ground substances B) Sinusoidal capillaries - Fibers B) Hematopoietic cords (developing blood cells) C) Sinusoidal capillaries  Questions Dr/ Shereen Elabd Regarding neutrophils, which of these statements is true? a. The nucleus is rounded b. Contain azurophilic granules only c. Contain acidophilic non-specific granules d. Barr body attached to one lobe of the nucleus in female Which of the following cells contains metachromatic granules obscure the nucleus? a. Monocyte b. Basophil c. Eosinophil d. Lymphocyte Which of the following is NOT a component of yellow bone marrow? a. Stroma b. Hematopoietic cords c. Fat cells d. Blood sinusoids  Dr/ Shereen Elabd Which of these cells contains elongated specific granules with crystalline core? a. Eosinophil b. Neutrophil c. Basophil d. Mast cell Which of the following cells has immunological role? a. Chondrocyte b. Unilocular adipocyte c. Plasma cell d. Fibroblast Which of the following belongs to reticylocyte NOT to erythrocyte? a. Free ribosomes b. Eccentric nucleus c. Haemoglobin d. Lack of nucleus  Dr/ Shereen Elabd A differential cell count of a blood smear from a patient infected with bilharzia is likely to reveal an increase in the circulating numbers of which cell type? a. Neutrophils b. Lymphocytes c. Monocytes d. Eosinophils What is the leucocyte has elongated granules with crystaline core? What is the leucocyte that differentiate out of bone marrow? Mention three cells associate to allergic reaction. What is the active bone marrow, and where is it located in adults?  Dr/ Shereen Elabd Thank You SUE