. Introduction A. The internal environment is regulated by thefluids which bathe the cells: 1. Interstitial fluid (IF) is found outside cellsand in between the cells 2. Lymph inside lymph vessels 3. Blood within blood vessels B. Hematology is the science which studies bloodand blood disorders
Blood Fluid connective tissue Functions include Transporting dissolved gases, nutrients, hormones, and metabolic wastes Regulating pH and ion composition of interstitial fluids Restricting fluid loss at injury sites Defending the body against toxins and pathogens Regulating body temperature by absorbing and redistributing heat
Composition of Blood Total Blood Volume : 5-6 liters (8% of body weight or 80ml/kg body weight) Specific Gravity : 1050-1060 Viscosity : 4-5 times that of water Ph : 7.4 (.05); it is alkaline in nature In acidosis Ph of blood falls below 7.38 and in alkalosis Ph is more than 7.42
Composition of Blood Blood contains plasma & formed elements(cells) Cells represent 45% of blood volume Hematocrit represents the percentage of red blood cells in blood (called Packed Cell Volume (PCV) 1. A lower than normal hematocrit is representative of a condition known as anemia 2. An abnormally high hematocrit is representative of polycythemia Hematocrit “ for males: 40%-54% (47%); Females: 38%-46% (42%)
Blood Components: Figure 16-1: Composition of blood
Blood Components: Cells Erythrocytes Red Blood Cells (RBC) O2 & CO2 transport White Blood Cells (WBC) Immune defense Phagocytosis Platelets: clotting
Plasma is a clear ,straw colored fluidportion of blood & represents 55% ofthe total blood volume. It contains 91% water and 9% solids( 1% inorganic molecules ,8% organicmolecules)
The major inorganic Of 8% organic molecules molecules are Na+ 7% are Plasma ,Ca++, Hco3-, K+ , Mg++, Cu++, Po4-3 Proteins (6.4-8.3 gm%) 1% are Non Protein Nitrogenous substances(urea,Uric acid,Creatinine,Xanth in)
. plasma composition 1. 92% water 2. 9% solutes a. Proteins -albumins; globulins (alpha, beta, gamma); fibrinogen b. Nutrients c. Enzymes d. Hormones e. Respiratory gases (oxygen, carbon dioxide) f. Electrolytes (sodium, chloride, potassium) g. Waste products (urea, uric acid, creatinine, H+, etc)
Globulins ~38% of plasma proteins Include immunoglobins which attack foreign proteins and pathogens Include transport globulins which bind ions, hormones and other compounds Fibrinogen Converted to fibrin during clotting Removal of fibrinogen leaves serum
Functions of Plasma Proteins Exert Osmotic Pressure : Contribution to Blood Viscosity Role in Coagulation of Blood Role in Defense Mechanism of Body Role in maintaining acid –base balance of body Transport Function
Exert osmotic pressure Plasma proteins can’t cross capillary membrane so exert colloidal osmotic pressure of about 25mmHg on capillary membrane. 80% of COP is contributed by Albumin COP plays an important role in exchange of water between blood & tissue fluid At arterial end of capillaries, due to high Hydrostatic Pressure than COP there occurs filtration of fluid out in tissues At venous end of capillaries due to lower HP than COP there occur absorption of fluid from tissues in to vessels
Contribution to Blood Viscosity Shape of Plasma Proteins Greatly contribute to Viscosity of Blood. Fibrinogen & globulins are main contributors due to their asymetrical shape The Blood Viscosity plays an important role in the maintenance of Blood Pressure by providing resistance to flow of blood .
Role in Coagulation of Blood The Fibrinogen ,Prothrombin & other coagulation proteins present in plasma play important role in the coagulation of Blood. Whenever ,there is injury to blood vessels, the fibrinogen is converted in to fibrin which form blood clot
Role in Defense The Gamma globulins are anti bodies which plays an important role in the immune system meant for defense of the body against the micro-organisms
Acid-Base Balance Plasma Proteins acts as Buffers Contribute for 15% buffering capacity of Blood PP are amphhoteric in nature means can combine with acids and bases. In Acidic Ph the NH2 group of the proteins acts as base & accept proton & is converted to NH4 In Alkaline Ph the COOH group of the protein act as acid & can donate a proton & thus become COO-
Transport Function PP can combine easily with many substances & play an essential role in their transport CO2 is transported by PP in the form of carb- amino compounds Thyroxine- is transported by an alpha – globuline called TBP Cortisol is transported by transcortin(mucoprotein)
Transport Function Vitamins A,D & E are transported by the high and low density lipoproteins. Bilirubin is transported with Albumin & also with fractions of alpha globulin. Drugs are transported with Albumin Ca++ of plasma is 50% bound to proteins for transport. Cu is bound to ceruloplasmin(alpha globulin) for transport Free HB in the vessels is bound to haptoglobin & is carried to reticulo-endothelial system
Causes of Albumin Deficiency Liver diseases (cirrhosis) – decrease in the ratio of albumin to globulins Protein malnutrition Excessive excretion by kidneys (renal disease) Mutation causing analbuminemia (affects splicing)
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