REOLOGICAL PROPERTIES OF BLOOD

Reology Reology is the about the flowing of blood. Reology is a strong friction which arise in the case of fluids’ layers moving with the different speed. Blood is the fluid tissue of inner environment of body, which consists of plasma, formed elements and cells.

Physical and chemical properties of blood Quantity of blood in adults is 6-8 % - in newborns – 15 %

Physical and chemical properties of blood Density of blood in adult is 1,055-1,060 g/sм3, plasma – 1,025-1,034 g/sм3. In newborns density is higher, than in adult.

Viscosity of blood Viscosity of blood determine by resistance, which is present in the case of moving the layers of blood. In adult viscosity of blood is near 5, viscosity of plasma is 1,5-1,7. In newborns viscosity is higher, than in adult.

Оsmotic pressure Оsmotic pressure determine by concentration of salts. It helps to support concentration of different substances on constant level. Hypertonic solution is solution with osmotic pressure higher than osmotic pressure in the cell. Hypotonic solution is solution with osmotic pressure less than osmotic pressure in the cell. Isotonic solution is solution with the same osmotic pressure that in the cell. Оsmotic pressure of blood is мосm/l.

Factors, which determines reological peculiarities of blood For plasma: viscosity, chemical substances, pH. For erythrocytes: possibility to deform, to aggregate.

Form elements, cells. Erythrocytes: in males is 4,0-5,1 Т/l, In females – 3,7-4,7 Т/l, In newborn is (5,9-6,7)10 12 /l or 5,9-6,7 Т/l. Leukocytes: in adult is (4-9)10 9 /l or 4-9 G/l, in newborn is (16,7-30,0)10 9 /l or 16,7-30,0 G/l. Platelets are the same in adult and children ( )10 9 /l or G/l.

Proteins of plasma At norm it g/l of proteins. In newborn it less concentration. Albumins is g/l. In newborn it less concentration. Globulins are: α 1 globulins – 1-4 г/л α 2 globulins – 4-8 г/л β globulins – 6-12 г/л γ globulins – 8-16 г/л Concentration of γ globulins is higher in newborn. Fibrinogen is 2-4 g/l.

Erythrocytes speed sedimentation (ESS) Erythrocytes speed sedimentation in male is 2-10 mm per hour, in female is 2-15 mm per hour, in newborn is 1-2 mm per hour.

Factors, which determinate erythrocytes speed sedimentation 1. erythrocytes’: а) quantity of erythrocytes: in case of erythrocytes increase ESS decrease; б) size of erythrocytes: increase volume – increase ESS; в) hemoglobin: less quantity less ESS; г) electrical charge of erythrocytes: less of negative charge lead to increase of ESS. Plasma’: а) increase of globulins – increase ESS; б) increase of fibrinogen – increase ESS; в) increase of cholesterol increase ESS; г) increase of рН (>7.45) increase ESS.

Hemolysis of erythrocytes Hemolysis of erythrocytes is the process of breaking the erythrocytes and hemoglobin go out from erythrocytes. There are 2 kinds of erythrocytes: physiological and pathological. It can be osmotic, mechanical, termical, chemical, biological.

Period of blood poises in fetus 1. Extra embryo 2. Liver 3. Bone marrow

Hemostasis Hemostasis is the physiologic system, which support the blood in the fluid condition and prevent bloodless.

The components of hemostasis wall of the vessels, blood cells – platelets, erythrocytes, leucocytes, enzymes and nonenzymes components of plasma – clotting and anticlotting substances, fibrinolysis components of hemostasis.

Kinds of hemostasis vessel-platelets (primary) begin the first after the destroyed of vessels. coagulative (secondary) hemostasis add after that in case the primary hemostasis do not stopped the bloodless.

Functions of platelets 1. hemostatic function – produce 12 factors, which are secure the hemostasis. 2. Angiotrophic function 3. Transport function 4. Phagocytosis function. 5. Regeneratory function

Stages of vessel-platelets hemostasis 1. Shorting spasm of the vessels 2. Adhesion of platelets 3. Reverse aggregation of platelets 4. Unreverse aggregation of platelets 5. Retraction of platelets plug

Investigation of vessel-platelets hemostasis 1. Calculation of the platelets quantity 2. Determination of duration of capillary bleeding after Duke’s method – to 3 minute in norm. 3. Sample of fragility of capillars – to 10 petechias in norm in a round with diameter 5 centimetres.

Clotting factors I – fibrinogen; II – prothrombine; III – thromboplastin of tissue; IV – ions of calcium; V – proaccelerin; VII – proconvertin; VIII – antihemophylic factor A; IX – Christmas factor or antihemofilic factor B; X – Stuart-Prower factor or prothrombinase; XI – plasma thromboplastin antecedent; XII – Hageman factor; XIII – fibrin stabilizing factor.

External mechanism of the first stage 3 factors from the injure tissues go to plasma and interactions with VII factor, the last is activated. VII active factor and IV factors form the complex 1a: III + VII active + IV, which is activated X factor

Inner mechanism of the first stage Factor 3 of platelets – platelets thromboplastine – influence on XII factor. Active XII factor + XI is complex 1. Active XI factor activated IX factor. Active IX factor + VIII factor + IV factor is complex 2. Complex 1a and 2 are activate X factor. Factor X active + V + IV formed complex 3 or thrombinasa complex.

second and third stages The second stage – formation of thrombin from prothrombin. The third stage is formation of fibrin from fibrinogen. The last stage has 3 period; formation of fibrin- monomers; formation of fibrin S (solubilis); formation of fibrin I (insolubilis). Calcium is necessary for all stages.

Valuation of clotting Time of clotting by Ly-Wait – 5-10 minutes; time of plasma recalcification – seconds; thrombotest – IV, V, VI degree; thromboplastin time – seconds; thromboplastin index – %; concentration of fibrinogen – 2-4 g/L; tolerancy of plasma to heparin – 6-11 minutes; heparin time – seconds; fibrinolysis – %.

Role of vessels endothelium in support blood in the fluid condition 1. Smooth surface of vessels endothelium. 2. Negative charge of endotheliocytes and blood cells and that’s why they are push away. 3. Present on the vessels wall thin layer of fibrin which adsorb clotting factors, especially thrombin. 4. Constant presence in blood anticlotting factors in a small doses. 5. Producing by endothelium prostaciclins, which are powerful inhibitors of platelets aggregation. 6. Ability of endothelium to produce and fix antithrombin-III.

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