Heamatology No (1).pdf

Introduction To Hematology Faculty Of Medicine Dept. Of Physiology Blood ❑Composition – Fluid part plasma – Cellular elements Erythrocytes Leucocytes thrombocytes Physical Characteristics ❑Adult ♂ contains 5-6L ❑Adult ♀ contains 4-5L ❑T is about 100.4 F (37 c)....

Introduction To Hematology Faculty Of Medicine Dept. Of Physiology Blood ❑Composition – Fluid part plasma – Cellular elements Erythrocytes Leucocytes thrombocytes Physical Characteristics ❑Adult ♂ contains 5-6L ❑Adult ♀ contains 4-5L ❑T is about 100.4 F (37 c). ❑5 times as viscous as water – Is it more or less resistant to flow than water? – What accounts for its viscosity? ❑pH ranges from 7.35 – 7.45 (slightly alkaline) ❑Color ranges from scarlet (oxygenated blood) to a deep red (deoxygenated blood).  Functions of Blood Transports: ▪ Nutrients Defense: ▪ Electrolytes ▪ Foreign organisms ▪ O2 & CO2 ▪ Injury/infection ▪ Waste Products ▪ Clotting process ▪ Hormones ▪ Body temperature Maintains Homeostasis Components of blood  Hematocrit ❑Percentage of blood occupied by cells – female normal range 37 - 47% (average of 42%) – male normal range 40 - 50% (average of 45%) testosterone ❑Anemia – no enough RBCs or no enough hemoglobin ❑Polycythemia – too many RBCs (over 65%) – dehydration, tissue hypoxia.  Blood Cells ❑There are 3 Cellular components to blood A. Red Blood Cells (RBCs) B. White Blood Cells (WBCs) C. Blood Platelets (PLs) Human Blood Smear Blood vessel White blood cell Red blood cell Platelets Plasma  Review of Blood Components Blood Plasma Blood Cells and Blood Parts White Blood Cells(W.B.C) Platelets Red Blood Cells (R.B.C) -Leucocytes -Erththrocytes Macrophages Lymphocytes  Formation of Blood Cells ❑Most blood cells types need to be continually replaced ❑Die within hours, days or weeks ❑process of blood cells formation is hematopoiesis or hemopoiesis  Sites of hematopoiesis ❑Embryo – Yolk sac (1st three month) – Liver and spleen: – 4-7th month of gestation – Bone marrow-7th month ❑At birth – The whole bony skeleton contains active marrow ❑Childhood and adolescence – Decrease in long bones Sites of hematopoiesis ❑Adults - After the age of 20,the red marrow: – Limited to flat bones (skull, ribs, vertebrae, pelvis,..) – Proximal ends of long bones. 25% RBCs precursors 75% WBCs precursors  Bone marrow ❑One of the largest organs in the body. ❑Represents 5% of total body weight. ❑It consists of cellular component (red marrow) separated by fat (yellow marrow). ❑It is the site of production of all types of blood cells ❑All blood cells are derived from a single type of cell in the bone marrow this is: ❑The multipotent uncommitted stem cell Bone marrow ❑MPUCSC differentiate into committed stem cell ❑The committed stem cells then develop into RBC,WBC,PLATELETS The Bone Marrow ❑Developing cells are held within normal marrow until they have developed sufficiently to function normally. ❑Then they are released into the circulating blood for the remainder of their life span. Hematopoiesis Stages of Blood Cell Formation ❑Pluripotent stem cells.1% of red marrow cells they differentiate into either myeloid or lymphoid stem cells ❑Myeloid stem cell line of development continues: – progenitor cells(colony-forming units) are specialized to form specific cell types example: CFU-E develops eventually into only red blood cells – next generation is blast cells have recognizable histological characteristics develop within several divisions into mature cell types ❑Lymphoid stem cell line of development – develop into lymphocytes in the lymphatic tissue after leaving the red marrow Hemopoietic Growth Factors ❑Regulate differentiation & proliferation Erythropoietin (EPO) produced by the kidneys increase RBC formation Thrombopoietin (TPO) hormone from liver stimulates platelet formation Cytokines are local hormones of bone marrow (IL-1, IL-3, IL4,5,6,9 & 11) produced by some marrow cells to stimulate proliferation in other marrow cells colony-stimulating factor (CSF) & interleukin stimulate WBC production.  Medical Uses of Growth Factors ❑Available through recombinant DNA technology ❖recombinant erythropoietin (EPO) very effective in treating decreased RBC production of end-stage kidney disease ❖other products given to stimulate WBC formation in cancer patients receiving chemotherapy which kills bone marrow granulocyte-macrophage colony-stimulating factor granulocyte colony stimulating factor ❖thrombopoietin helps prevent platelet depletion during chemotherapy  Erythropoiesis and erythrocytes ❑ Lifespan – 120 days ❑ Non nucleated ❑ Biconcave disc ❑ Production regulated by Epo ❑ Needs Fe, B12, folate & other elements for development Erythropoiesis Development of mature red cells  Contents ❑No nucleus and there for no reproduction ❑No mitochondria and there for no aerobic glycolysis ❑Contain haemoglobin ❑Count of RBCs -In male: 4.8-5.8 million/mm3 -In female: 4.2-5.2 million/mm3  Control of Erythropoiesis ❑Erythropoiesis is stimulated by erythropoietin (EPO) hormone ❑Secretion of EPO is stimulated by: ❑Hypoxia (low oxygen) – Anaemia – Hemorrhage – High altitude – Lung disease – Heart failure Role of the kidneys in RBC formation Tissue oxygenation and RBC formation Control of erythropoiesis Cont. ❑Erythropoietin glycoprotein 90% from renal cortex 10% from liver Stimulates the growth of: early RBC-committed stem cells Can be measured in plasma & urine High level of erythropoietin –anemia –High altitude –Heart failure Control of erythropoiesis cont. ❑Other hormones Androgens, Thyroid, cortisol & growth hormones are essential for red cell formation Deficiencies of any one of these hormones results in anaemia  Erythropoietin ❑functions: - stimulate self replication and proliferation of erythrocyte stem cells. - Stimulate differentiation to proerythroblast. - stimulate haemoglobin synthesis. - Stimulate maturation of RBCs - human erythropoietin can be produced by DNA recombinant technology (CRF