Composition of blood

Plasma Proteins ,Function ,Types,Synthesis.First MBBS Lecture

1. Blood Dr Raghuveer choudhary Composition and function of

2. .       Introduction         A.  The internal environment is regulated by the fluids which bathe the cells:              1. Interstitial fluid ( IF ) is found outside cells and in between the cells               2 . Lymph inside lymph vessels               3. Blood within blood vessels         B. Hematology is the science which studies blood and blood disorders

3. THE BLOOD Blood is defined as liquid connective tissue that fills the heart and blood vessels. The normal blood volume in an average adult is 5–6 liters , which accounts for about 8% of the body weight.  

4. 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

5. Figure 19.1a The Composition of Whole Blood

6. 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

7. Figure 10.1

8. 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% )

9. Blood Components: Figure 16-1: Composition of blood

10. Blood Components: Cells Erythrocytes Red Blood Cells (RBC) O 2 & CO 2 transport White Blood Cells (WBC) Immune defense Phagocytosis Platelets: clotting

11. Blood Cells

12. Plasma is a clear ,straw colored fluid portion of blood & represents 55% of the total blood volume. It contains 91% water and 9% solids ( 1% inorganic molecules ,8% organic molecules)

13. The major inorganic molecules are Na + ,Ca ++ , Hco 3 - , K + , Mg ++ , Cu ++ , Po 4 -3 Of 8% organic molecules 7% are Plasma Proteins (6.4-8.3 gm%) 1% are Non Protein Nitrogenous substances(urea,Uric acid,Creatinine,Xanthin )

14. . plasma composition            1. 91% water            2.   9% solutes                   a . Proteins -albumins; globulins ( alpha , beta , gamm a); 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)

15. Figure 10.1

16. Plasma Water Plasma proteins Albumin (60%) Osmotic Gradient Globulins (Ab) Fibrinogen Other solutes Electrolytes Nutrients Trace Elements Dissolved gases Serum = Plasma – Clotting factors

17. Serum = Plasma – Clotting factors

18. Fresh Frozen Plasma: In some conditions, plasma needs to be stored for years for future analysis, for which plasma is stored frozen below –20 ᴏ C. This is called fresh frozen plasma (FFP ), which can be stored upto 7 years in a blood bank. To preserve clotting factors plasma should be frozen within 6 hours after collection. FFP is used for plasmapheresis (therapeutic plasma exchange).

19. Plasma Proteins Albumin Globulin- α₁ , α₂ , β₁ , β₂ , γ Fibrinogen Origin: Liver - Albumin & Fibrinogen Plasma cells, lymphocytes, tissue macrophages- Globulin

20. Plasma proteins concentration 63 –83 g  l (6.3-8.3gm%) s imple or conjugated (glycoproteins, lipoproteins) separation: a) salting-out methods  albumin , globulins , fibrinogen b) electrophoresis  albumin, globulin  1 ,  2 , ,  fractions : - +    2  1 albumin

21. Albumins more than 90% are synthesized in the liver 55% of plasma proteins 3-5 gm% (average 4.8gm%) Functions: m aintenance of the osmotic pressure of plasma and viscosity t ransport of: steroid hormones free fatty acids bilirubin drugs (sulfonamides, aspirin) Ca 2+ Cu 2+

22. Plasma Proteins- GLOBULINS Globulin is 38%of plasma Proteins 2-3 gm%(average 2.3gm%) 13% α globulin : 0.79-0.84 gm% 14% β globulin : 0.78-0.81 gm% 11% γ globulin : 0.66-0.70 gm% A/G ratio :1.7-1 7% Fibrinogen: 0.3 gm% Prothrombin: 40 mg %

23. Elfo fractions of plasma proteins Fraction Rel. amount (%) c (g) Albumins : albumin pre-albumin (transthyretin) 52 – 58 34 – 50  1 -globulins : thyroxin-binding globulin, transcortin,  1 -acid glycoprotein,  1 -antitrypsin,  1 -lipoprotein (HDL),  1 -fetoprotein 2,4 – 4,4 2-4  2 -globulins : haptoglobin, macroglobulin, ceruloplasmin 6,1 – 10,1 5 – 9 -globulins : transferrin, hemopexin, lipoprotein (LDL), fibrinogen, C-reactive protein, C3 and C4 components of the complement system 8,5 – 14,5 6 – 11 -globulins : IgG, IgM, IgA, IgD, IgE 10 – 21 8 – 15

24. 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

25. 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

26. 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

27. Functions of Plasma Osmotic pressure: Plasma proteins are osmotically active molecules, and the osmotic pressure of plasma due to plasma proteins is called oncotic pressure . The normal oncotic pressure is 25 mmHg . This pressure helps in maintaining volume of the vascular compartment. .

28. Oncotic pressure retains fluid in the vascular compartment and therefore, prevents loss of fluid from capillaries into the interstitial tissue space (functionally, it opposes the action of hydrostatic pressure). The oncotic pressure is due to the presence of albumin in the plasma.

29. 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 .

30. 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

31. 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

32. 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 NH 2 group of the proteins acts as base & accept proton & is converted to NH 4 In Alkaline Ph the COOH group of the protein act as acid & can donate a proton & thus become COO -

33. Transport Function PP can combine easily with many substances & play an essential role in their transport CO 2 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)

34. 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

35. Labile protein store : Plasma proteins serve as mobile protein reserve( as the source of amino acid for tissues ) of the body, which can be utilized for tissue growth, especially in situations of protein depletion.

36. 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)

37. Variations in plasma protein levels Reduced albumin: Infancy Pregnancy Hepatitis Cirrhosis Nephrosis burns Increased globulin : Cirrhosis of liver Tuberculosis Lymphatic leukemia Decreased Fibrinogen: Congenital DIC Increased Fibrinogen: Pregnancy malaria