Blood

  • Research methods the blood, the hemoglobin
  • Features of the blood of children
  • Blood products
  • Forensic analysis of blood
  • Blood is a liquid tissue, continuously moving through the vessels, which penetrates into all body tissues and linking them with each other. The function of blood diverse: 1) the transport of oxygen from the lungs to the tissues and carbon dioxide from the tissues to the lungs (respiratory function); 2) the transfer of nutrients from the place of their arrival to the place of their consumption (nutrient function); 3) transfer disposal of products of exchange to the excretory organs; 4) the transfer of hormones and enzymes from the place of their production to places of their activity; 5) maintaining the constancy of the internal environment of the body (constant osmotic pressure, water balance, mineral composition); 6) the maintenance of a constant body temperature; 7) protection of the organism from penetrating into it harmful agents by using antibodies (see) and phagocytosis (see). The blood is about 7% (1/11-1/13 part) of body weight. The amount of blood in men average of 5.5 litres and women - 4,5 L. It is a suspension of formed elements - of erythrocytes (see), leukocytes (see), and platelets (see) in the plasma. Volumetric ratio of these two parts of the blood is determined by the hematocrit (see). In norm the formed elements take about 45% of the volume, plasma - about 55%. Anemia volume occupied shaped items, decreases in polycythemia increases. The blood and blood-forming organs (see) are linked in a common system, called the blood system. The movements of the blood of a healthy person due to a number of regulatory mechanisms (see the Blood) is relatively constant. Changes can be of diagnostic value. Especially profound changes of morphological and biochemical composition of blood are observed in diseases of the blood system (see Anemia, Leukemia, Myeloma, Polycythemia, thrombocytopenic Purpura. Retikulez). Scarlet arterial blood depends on the oxyhemoglobin, dark red color of venous blood from the restored hemoglobin(so). The proportion of blood 1,060 men 1,056 women. The reaction of the blood slightly alkaline (pH of 7.35-7,47). Due to the salt content of protein and blood has colloid-osmotic pressure, that is able to retain a certain amount of water. The constancy of the osmotic pressure of blood is very important for all the body's cells, including red blood cells, which in hypotonic solutions swell and gemosideros, and in hypertensive - shrink. Isotonic against blood is 0.9% solution of sodium chloride. Blood viscosity determined by viscometer, 5 times higher than the viscosity of water.
    Blood plasma contains 90% water, 7-8% protein, various salts, carbohydrates, lipids, intermediate products of metabolism, hormones, enzymes, components of the coagulation system, vitamins, pigments, dissolved gases, etc. In blood coagulation dissolved in plasma fibrinogen transformed into insoluble fibrin, which formed as a result of a blood clot (see blood Clotting ). After some time there is a reduction (retraction) of the bunch, he pressed serum - transparent liquid, tinged with bilirubin in yellow, with all components of plasma, except fibrinogen. Studies of most chemical components of blood are produced in the serum.