Dr.n.n.kumari MBBS-Year I term1 MCBM 1 Element 2 Lec-16

Dr.n.n.kumari Plasma Proteins Composition of plasma Packed cell volume (haematocrit) Relationship between plasma volume and blood volume Physiologic functions of plasma proteins

Dr.n.n.kumari Give the composition of plasma Write a detailed account of the functions of plasma proteins. Explain the role of starlings forces in tissue fluid formation Define edema ? Explain the factor that cause edema. How do you obtain a sample of plasma & serum

Dr.n.n.kumari Hematocrit or packed cell volume The Percentage of the RBC in the blood is called hematocrit Hematocrit is determined by centrifuging blood mixed with an anticoagulant in the hematocrit tube at 3000 rpm for 30 min

Dr.n.n.kumari COMPOSITION OF BLOOD 1.Plasma :- Plasma proteins, Inorganic & organic substances 2.Formed elements RBC, WBC & platelets

Dr.n.n.kumari Blood Composition Formed elements 45% Plasma 55% Erythrocytes (RBC) Leucocytes (WBC) Thrombocytes (Platelets ) 90% water 10 % solids

Dr.n.n.kumari Plasma Proteins 7% Albumin Globulin Fibrinogen Prothrombin Non-protein nitrogenous substances Urea Uric acid Creatine Creatinine Xanthine Hypoxanthine Organic Glucose Aminoacids fatty acids phospholipids cholesterol hormones enzymes antibodies Inorganic substances Na + K + Ca 2+ Mg 2+ Fe 2+ Cu I & Cl -

Dr.n.n.kumari Plasma proteins Concentration g/dl Classification of plasma proteins Serum Albumin 3.5 – 5.0 g% Serum Globulin 2.0 – 3.5 g% Fibrinogen g%

Dr.n.n.kumari Plasma protein Concentration G% Molecular weight Albumin (4.5)69000 Globulin2.0 – 3.5 (2.7)90000 to Fibrinogen0.2 – 0.3 (0.25) to Concentration of Plasma proteins

Dr.n.n.kumari Variations in the amount of plasma proteins Protein fraction IncreaseDecrease FibrinogenPregnancy Menstruation Tissue injuries, Acute diseases Hepatectomy Liver diseases haemorhage Globulin ( α 1 α 2,β & γ ) Liver diseases Multiple myeloma Acute nephrites Leukemia Tuberculosis

Dr.n.n.kumari Albumin Cirrhosis, other liver diseases, kidney diseases nephritis, nephrosis Normal A:G ratio in the blood is 3:2.In all the above mentioned cases there is no absolute increase in globulin, but there is relative increase in globulin due to decrease in albumin synthesis. The A:G ratio is reversed-2:3.

Dr.n.n.kumari Colloidal Osmotic Pressure (COP) or Oncotic pressure The COP of blood & plasma is about 25 mm Hg. COP is due to plasma proteins. 80% of it (20 mm Hg) is exerted by serum albumin. 20% i.e. 5 mm Hg is exerted by globulin & fibrinogen

Dr.n.n.kumari Functions of plasma proteins 1.Colloidal osmotic pressure 2.Coagulation of blood 3.Defence Mechanism 4.Buffering action 5.Transport of substances 6.Protein reserve 7.Viscosity of blood 8.Erythrocyte sedimentation rate

Dr.n.n.kumari Functions of albumin 1. Maintains colloidal osmotic pressure. Albumin is responsible for 80% of total COP ( 20 mmHg ) 2.Transports unconjugated bilirubin, drugs & CO 2 3. Buffering action 4. Viscosity

Dr.n.n.kumari Functions of Globulins 1.Enzymatic functions in plasma 2.Natural & acquired immunity 3.Viscosity 4.Acid – Base balance 5.Clotting of blood 6.Transportation of CO 2 thyroxine & cortisol

Dr.n.n.kumari Starling’s forces

Dr.n.n.kumari

Dr.n.n.kumari Arterial end HSP = 37-1=36 mmHg COP = 25 mmHg Net filtration pressure = = 11mm Starling’s hypothesis of tissue fluid formation Venous end HSP = 17 mmHg COP = 25 mmHg Net Pressure = = 8 mmHg

Dr.n.n.kumari Functions of Fibrinogen 1. Clotting of blood 2. Viscosity 3. Acid - base balance 4. Colloidal osmotic pressure

Dr.n.n.kumari FunctionProteins responsible Maintain colloidal osmotic pressure A>G>F Clotting of blood F & G ViscosityF > A > G Acid-Base balance Protein store All proteins. Rouleaux formationF&G

Dr.n.n.kumari Mechanism of Clotting 1.Formation of intrinsic & extrinsic prothrombin activator 2. Prothrombin Thrombin 3.Fibrinogen Fibrin monomer Fibrin polymer Cross-linked fibrin polymer (clot)

Dr.n.n.kumari Source of plasma proteins 1. Amino acids from food 2. From tissue proteins in conditions of protein starvation

Dr.n.n.kumari Origin of plasma proteins Albumin, most globulins & Clotting factors of blood (Fibrinogen & Prothrombin are formed in the Liver The γ– globulins (antibodies) are formed by plasma cells & B- lymphocytes

Dr.n.n.kumari Causes of albumin deficiency ( Hypoalbuminemia ) Decreased synthesis — Cirrhosis of liver Decreased production - Malnutrition (as in starvation) Excess excretion by the Kidneys (as in nephrotic syndrome) Excess loss in bowel (protein losing enteropathy)

Dr.n.n.kumari Edema W hat is edema? Edema is excessive accumulation of fluid in the tissue spaces. There is much swelling & when the pressure applied with the thumb over the region is released, there is a depression due to movement of fluid away from the region and is called ‘pitting on pressure’.

Dr.n.n.kumari Features of Kwashiorkor:  Retarded growth  Pot belly  Thin swollen legs  Lethargy  Depressed mentation  Edema 1.Protein deficiency syndrome

Dr.n.n.kumari Factors involved in Edema 1.Increased capillary Hydrostatic pressure 2.Reduced Plasma colloidal osmotic pressure 3.Increased capillary permeability & surface area 4.Obstruction to lymphatic drainage

Dr.n.n.kumari Edema continued 2.In Liver diseases (cirrhosis of liver, portal obstruction) Diminished synthesis  Decrease in Plasma proteins concentration  decreased colloidal osmotic pressure  retention of fluid (Edema ) 3.Renal diseases: Due to loss of Proteins in urine

Dr.n.n.kumari Pitting edema Accumulation of fluid caused due to disturbance s in the fluid exchange mechanisms across the capillary pitting