BLOOD AND BODY DEFENCE Dr. Amel Eassawi Dr. Abdelrahman Mustafa 1

HMIM 224 L1: PLASMA PROTEINS 2

OBJECTIVES The student should be able to:  Describe the composition of blood.  Enumerate different plasma proteins.  Explain the functions of plasma protein.  Correlate the changes in plasma proteins with the clinical conditions. 3

BLOOD Represents about 8% of total body weight. Average volume: –5 liters in women. –5.5 liters in men. Composed of two parts: 1. Plasma (liquid portion of blood). Average normal volume: –58% in women. –55% in men. 2. Cellular elements. 4

BLOOD 5

3 Types of Specialized Cellular Elements: –Erythrocytes Red blood cells Important in O 2 transport –Leukocytes White blood cells Immune system’s mobile defense units –Thrombocytes Platelets (cell fragments) Important in hemostasis 6  Hematocrit or packed cell volume represents the percentage of Erythrocytes in the total blood volume.  Average normal volume: - 42% in women - 45% in men

BLOOD Functions of Blood: 1. Transport: –Respiratory gases (O2 & CO2) –Nutrients –Metabolites –Hormones –Drugs –Enzymes 2. Defense against infection. 3. Maintenance of: –Body temperature. –Acid-Base balance. –Fluid-Electrolyte balance. 7

PLASMA ConstituentsExample Water Makes up 90% of plasma. Electrolytes Na +, K +, Cl -, HCO 3 – ProteinsAlbumin, Globulin, Fibrinogen CarbohydratesGlucose LipidsCholesterol, fatty acids MineralsCa 2+, PO 4 3- EnzymesAlkaline Phosphatase, Amylase MetabolitesBilirubin, Urea, Uric acid, Creatinine 8

PLASMA PROTEINS Plasma proteins: –Compose 6% to 8% of plasma’s total weight –3 groups of plasma proteins Albumins –Most abundant plasma proteins Globulins –3 subclasses »Alpha (α) »Beta (β) »Gamma (γ) Fibrinogen 9

PLASMA PROTEINS Plasma proteinAverage concentration Albumin4.8 g/100ml Globulins2.3 g/100ml Fibrinogen0.3 g/100ml Total7.4 g/100ml 10

PLASMA PROTEINS Plasma proteinFunction LipoproteinNutrients Alkaline Phosphatase, AmylaseEnzymes AngiotensinHormone γ - GlobulinAntibodies Fibrinogen, ProthrombinClotting factors Albumin, Ceruloplasmin, TransferrinCarriers Gasoline, Gc proteinScavengers 11

ALBUMIN Synthesized in liver gms each day and half life is 20 days. Exerts about 80-90% of the plasma colloid osmotic pressure. It forms about 60% of total plasma protein. Decrease in albumin (hypoalbuminaemia) result in fluid leaves the circulation causing edema (accumulation of fluid in the interstitial fluid). Causes of hypoalbuminaemia are: malnutrition, liver disease, kidney disease. 12

GLOBULINS Subdivided into α 1, α 2, β and γ Alpha and beta globulins are synthesized in liver. γ- gamma globulins are synthesized in reticuloendothelial system by plasma cells. 13

FUNCTIONS OF PLASMA ConstituentFunctions Water (makes up 90% of plasma) Transport medium, carries heat ElectrolytesMembrane excitability; osmotic distribution of fluid between ECF and ICF; buffer pH changes Plasma proteinsIn general, exert an osmotic effect important in distribution of ECF between vascular and interstitial compartments; buffer pH changes AlbuminsContribute most to colloid osmotic pressure. Transport many substances such as bilirubin, bile salt and penicillin Alpha globulinsTransport water insoluble substances such as lipoproteins, lipids, hormones: cortisol binding globulin, thyroid binding globulin. Beta globulinsTransport lipids, cholesterol, iron and copper. Gamma globulinsAntibodies FibrinogenBlood Clotting, Blood Viscosity

REFERENCES  Human Physiology, Lauralee Sherwood, seventh edition.  Text book Physiology by Guyton &Hall,11 th edition.  Text book of Physiology by Linda S. Contanzo, third edition.  Physiology by Berne and Levy, sixth edition. 15