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Objectives

Objectives. At the end of this lecture student should be able to: Describe Cellular and non-cellular components of blood Recognise functions of blood Define Erythropoiesis; leucopoiesis, thrombopoiesis . Recognize sites of RBC formation at different developmental age. Objectives.

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Objectives

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  1. Objectives At the end of this lecture student should be able to: • Describe Cellular and non-cellular components of blood • Recognise functions of blood • Define Erythropoiesis; leucopoiesis, thrombopoiesis. • Recognize sites of RBC formation at different developmental age Dr Sitelbanat september2011

  2. Objectives At the end of this lecture student should be able to: • Describe different stages of RBC differenation. • Describe features of RBC maturation. • Describe regulation of RBC production and erythropoietin hormone secretion in response to hypoxia. • Recognize clinical conditions associated with high level of erythropoitein in the blood Dr Sitelbanat september2011

  3. Lecture - 1 Topic: Red Blood Cells (RBCs))))) • Composition & functions of the Blood • Morphological Features of RBCs. • Production of RBCs • Regulation of production of RBCs

  4. Blood Composition

  5. Blood Film

  6. BLOOD COMPOSITION • Cellular components • Red Blood Cells (Erythrocytes) • White Blood Cells (Leucocytes) • Platelets (Thrombocytes) • Plasma • 98% water, ions, plasma proteins (Albumin, globulin, Fibrinogen) • Same ionic composition as interstitial fluid Dr Sitelbanat

  7. FUNCTIONS OF BLOOD • Transport • O2, CO2, nutrient, hormones, waste product • Homoeostasis • Regulation of body temperature, ECF pH • Protecting against infections • White Blood Cells, Antibodies • Blood clotting prevent blood loss Dr Sitelbanat

  8. Blood Volume • 5 liter in adult • 45% is packed cells volume (PCV) • 55% is plasma volume Dr Sitelbanat

  9. Blood Cells Formation • Erythropoiesis: Formation of RBC (erythrocytes) • Leucopoiesis: Formation of WBC (leucocytes) • Thrombopoiesis: Formation of platelets (thrombocytes) Dr Sitelbanat

  10. Red Blood Cells • Function • O2 transport • CO2transport • Buffer Dr Sitelbanat

  11. Red Blood Cells • Shape & size • Flat Biconcave Disc • Non-nucleated • Diamter 7-8 mm x 2.5 mm , 1 mm • Average volume 90-95 mm3 • Flexible • Number =4.7-5 x106 • Hb =34g/dl of cells • Hb= 14-16 g/dl in the blood Dr Sitelbanat

  12. Production of RBC • Early few weeks of embryo nucleated RBCs are formed in yolk sac. • Middle trimester mainly in liver & spleen & lymph nodes. • Last months RBCs are formed in bone marrow of all bones • Bone marrow of flat bone continue to produce RBC into adult life • Shaft of long bonestop to produce RBC at puberty while epiphysis continued Dr Sitelbanat

  13. Production of RBC Dr Sitelbanat

  14. Genesis of RBC • All blood cell are formed from Pluripotential hematopoietic stem cells committed cells: • Committed stem cells for RBC • Committed stem cells for WBC • Growth of different stems cells are controlled by different growth factors Dr Sitelbanat

  15. Stages of differentiation of RBC • Stages of RBC development • Committed stem cell • Proerthroblast • basophil erythroblast • polychromatophil erythroblast • orthochromatic erythroblast • Reticulocytes • Mature erythrocytes • Rapid RBC production   reticlocytes in the circulation Dr Sitelbanat

  16. Erythropoiesis • RBC development is characterize by: • decrease in cell size • disappearance of nuclus • appearance of haemoglobin Dr Sitelbanat

  17. Regulation of RBC production • Erythropoiesis is stimulated by erythropoietin hormone produced by the kidney in response to hypoxia (low oxygen in the blood) • Hypoxia caused by: • Low RBC count (Anaemia) • Hemorrhage • High altitude • Prolong heart failure • Lung disease Dr Sitelbanat

  18. Tissue oxygenation and RBC formation Dr Sitelbanat

  19. Erythropoietin • Glycoprotein • 90% from renal cortex 10% liver • Stimulate the growth of early stem cells • Does not affect maturation process • Can be measured in plasma & urine • High levels of erythropoietin • anemia • High altitude • Heart failure • Lung Disease (Result in polycythemia)

  20. Role of the kidneys in RBC formation Dr Sitelbanat

  21. Objectives At the end of this lecture student should be able to: • Describe Cellular and non-cellular components of blood • Recognise functions of blood • Define Erythropoiesis; leucopoiesis, thrombopoiesis. • Recognize sites of RBC formation at different developmental age Dr Sitelbanat september2011

  22. Objectives At the end of this lecture student should be able to: • Describe different stages of RBC differenation. • Describe features of RBC maturation. • Describe regulation of RBC production and erythropoietin hormone secretion in response to hypoxia. • Recognize clinical conditions associated with high level of erythropoitein in the blood Dr Sitelbanat september2011

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