Blood Physiology (Introduction) PDF

Blood physiology (Introduction) Dr Alabi Human physiology FULafia 1 Outline Introduction General composition Function Plasma proteins Origin Function Blood volume measurement Variations Regulation 2 I...

Blood physiology (Introduction) Dr Alabi Human physiology FULafia 1 Outline Introduction General composition Function Plasma proteins Origin Function Blood volume measurement Variations Regulation 2 Introduction Blood is fluid connective tissue contained in the cardiovascular system. Red in colour (arterial- bright red, venous purple red) oxygen concentration affects colour Constitutes about 8% of body weight (4.5 – 5L) Slightly alkaline (PH 7.4) 5X more viscous than water (rbc and plasma proteins) 3 General composition Blood cells – RBC (erythrocytes), WBC (leucocytes) and platelets (thrombocytes) Plasma : clear liquid portion of blood Blood = blood cells + plasma 4 Functions Transport Storage : protein, glucose Gases O2, CO2 Defense (immunity) Nutrients glucose, amino Phagocytes acids, lipids Waste products Immunoglobulin Hormones enzymes Homeostasis Regulation of water balance Acid base balance Body temperature 5 Plasma Plasma is a straw-colored clear liquid part of blood. It contains 92% to 93% of water and 7% to 8% of solids. The solids are the organic and the inorganic substances 6 Plasma proteins Serum albumin (55%) Globulins (alpha globulin (13%), beta globulin (14%), gamma globulin (11%) Fibrinogen Serum = Plasma - fibrinogen 7 Source In embryo – mesenchymal cells In adults – reticuloendothelial cells of the liver, spleen, bone marrow B-lymphocytes produce gamma globulins 8 Functions Coagulation – Clotting factors Immunity – gamma globulins Transport of hormones, enzymes, metals etc Homeostasis Acid-base balance , albumin, 15% of buffering capacity of blood Oncotic pressure – blood pressure Protein reservoir ESR 9 Variation 10 Plasmapheresis Therapeutic plasma exchange Procedure: venous blood is collected, cells separated from plasma, plasma is discarded, cells returned in saline or sterilized human albumin Myasthenia gravis, Thrombocytopenic purpura, LambertEaton myasthenic syndrome, GuillainBarré syndrome 11 Blood volume Blood vol about 5L, 2.8 to 3.1 L/sq M. Variation Age Sex Weight Exercise Pregnancy Altitude Emotion Pathologic 12 Regulation of blood volume Renal Hormonal ADH Aldosterone Cortisol ANP 13 Applied physiology Hypervolemia Hypovolemia Hyperthyroidism Hemorrhage Hyperaldosteronism Hemolysis CCF hypothyroidism Liver cirrhosis 14