Hematology PDF - First Lecture

First lecture Hematology Hematology: is the scientific study of blood structure and function in health and disease. Hematology is the study of blood, the bone marrow where blood is produced, and the hemostasis system. Disorders of lymph nodes and related tissues are...

First lecture Hematology Hematology: is the scientific study of blood structure and function in health and disease. Hematology is the study of blood, the bone marrow where blood is produced, and the hemostasis system. Disorders of lymph nodes and related tissues are also often included in the field of hematology. Hematology includes a wide variety of diseases, including genetic diseases (such as the hemoglobinopathies and thalassemias), immune diseases (such as immune hemolytic anemia), and malignancies (such as leukemia's and lymphomas). Historically, hematology has been important in many ways: in studying blood and its disorders, learning much about gene structure and function, the importance of chromosomal abnormalities in malignancies, the molecular biology of neoplasia, and many other things. Some of first successes in the treatment of neoplasia occurred in hematologic malignancies. Blood: is a mean for transportation in the body it takes about 6-8% of the body weight in a normal adult person. The amount of blood is about 5 liters of this 3 liters is present in the systemic veins, 1 liter in the arterial system and one liter present in the lungs. Blood has a specific gravity varies between individuals from 1.050 to 1.060 and it is viscosity 2-5 times that of water and blood salinity is 0.85. General functions of the blood 1- Respiration: transport of oxygen from the lungs to the tissues and Co2 from the tissues to the lungs to excreta. 2- Nutrition: transport of absorbed food materials from digestive system to other parts of the body. 3- Excretion: transport of metabolic wastes to the kidneys, lungs, skin and intestinal for removal. 4- Maintenance of normal acid-base balance in the body. Blood PH is 7.35-7.45. 5- Regulation of water balance through the effect of blood on the exchange of water between the circulating fluid and tissue fluid. 6- Regulation of body temperature by distribution of body heat, the blood temperature is 38C.  7- Defense against infection by the W.B.C.s and circulating antibodies. 8- Transport of hormones to regulation of metabolism and metabolites. Blood composition Blood composed from two phases: 1-Liquid phase which composed from water, electrolytes eg. Na, Ca, Hco3 and Cl, proteins and another substances like sugar, fat, vitamins and hormones. 2- Solid phase (formed elements) which are erythrocytes or Red blood cells, leukocytes or white blood cells (neutrophils, eosinophils, basophils, lymphocytes and monocytes) and platelets. Blood 55% 45% Plasma Solid phase Serum Fibrinogen R.B.C, W.B.C. and Platelets The difference between serum and plasma are serum has no fibrinogen, fibrin, factor ll, factor V, and factor Vlll. But it is rich in serotonin which is librated by aggregated platelet. PLASMA Normal adult plasma is 25-45ml/kg of body weight and its specific gravity is normally about 1.027. Plasma is a pale yellow fluid that consists of about 92% water ad 8% substances such as proteins, ions, nutrients, gases and waste products. Plasma proteins include albumin, globulin and fibrinogen. Albumin makes up 60% of the plasma proteins it makes an important contribution in osmotic pressure of blood & determined the movement of water into and out of the tissue and blood.Globulin account for 36% of the plasma proteins such as antibodies and complement; they are part in immune system. Fibrinogen constituents 4% of plasma proteins and is responsible for the formation of blood clot. Plasma volume remains relatively constant, normally water in take through the digestive tract and its loss through the kidneys, lungs, digestive tracts and skin. Composition of Plasma 1- Electrolytes: Include cations (Na+ ,K+,Mg++ ) and anions (Cl-, Hco3-, SO =, PO = ). 4 4 2- Proteins: They are many types like Albumin, Globulin, Fibrinogen, Transferrin, Heptoglobulin and Hemopoietin. 3-Other contents: Like cholesterol, triglycerides, lipoproteins, glucose, uria, uric acid, iron and coagulation factors. All plasma proteins are formed by liver except gamma-globulin produced by plasma cells. Functions of plasma proteins 1- Maintenance of osmotic pressure (oncotic pressure) at 25 mm/Hg , this symptoms made by albumin , hypoalbuminemia lead to reduction of oncotic pressure thus edema of subcutaneous tissue. 2-Transport system: many substances are carried in circulating by plasma, e.g. albumin carries Ca+2, bilirubin, sulpha drugs. Alpha-globulin carries B12, thyroxin (T3) and cortisol. Beta-globulin carries cholesterol, lipid, insulin, vitamin A, PO4, K +. Gamma-globulin carries histamine and antigens. 3- Protein reserve: Circulating plasma proteins are converted to amino acid by liver and they are reused by the cells. 4- Viscosity: viscosity of the blood depends on the size and shapes of protein molecules especially fibrinogen, hyperfibrinemia increased in blood viscosity 5- Buffering effect: To maintain pH (7.4), substance that has ability to donate H+ ions to alkaline solution or receive H+ ions from acid solutions. Protein has a buffering effect to maintain the blood pH at (7.4±0.5). 6-Antibody action: is made by gamma-globulins which they are formed by plasma cell and they are called (Ig).