Blood PDF 2021

Water distribution in the body: Total body water females – 50% males – 63% of the body weight ICF – intracellular fluid (>50 % of total body water) ECF – extracellular fluid (about 40 % of total body water) - circulating liquids - p...

Water distribution in the body: Total body water females – 50% males – 63% of the body weight ICF – intracellular fluid (>50 % of total body water) ECF – extracellular fluid (about 40 % of total body water) - circulating liquids - plasma (water, proteins, organic and inorganic compounds) - lymph - interstitial - tissue fluid TCF – transcellular fluid (1% of the body water) - cerebrospinal fluid (CSF), - eyes - pleura, peritoneum - joints - alimentary tract Functions of the blood: Transport functions - carries oxygen from the lungs to the cells - carries carbon dioxide from tissues to the lungs - waste products from tissues to the organs of excretion - kidneys - nutrients from the alimentary tract to the cells - hormones and vitamins transported to all parts of the body hormones are stored in the blood connected to plasma proteins Regulatory functions - acid - base balance mechanisms (pH regulation) - fluid and electrolyte balance, osmotic and oncotic pressure regulation - thermoregulation Protective function - clotting mechanisms prevent fluid loss through hemorrhage when blood vessels are damaged - immunologic reactions Composition of the blood -plasma -formed(morphotic) elements Plasma - the liquid portion of the blood - 90% water and 10% solutes Major types of plasma proteins: - albumins - globulins - fibrinogen Albumins - account for about 60 % of the plasma proteins - responsible for maintaining the oncotic pressure of the blood Globulins - account for 36 % of plasma proteins - lipid transport, immune reaction Fibrinogen - makes up the smallest fraction of plasma proteins - formation of blood clots Nonprotein molecules - uric acid - waste products - nutrients - gases - electrolytes Hematocrite - the ratio of morphotic elements to total blood volume Formed (morphotic) elements - Erythrocytes = red blood cells (RBC) - 4,5 - 6 millions /mm3 - structure - hemoglobin - function – oxygen and carbon dioxide transport - hemopoiesis (RBC production) - reticulocytes - anemia Leukocytes = white blood cells (WBC) - 5 000 - 9 000 /mm3 Granulocytes - neutrophils (60-70 % of total WBC) - eosinophils (2-4%) - basophils ( 7 - alkalinity - the lower the pH – the higher acidity - pH = 8 means that there is 10 times less hydrogen ions then when pH = 7 - cells constantly produce excessive amounts of acids (hydrogen ions) - constant pH is vital for the normal function of metabolic processes in the body - excessive ions must be neutralized - blood plays an important role in acid buffering Buffer systems in the blood: - phosphate buffer (H2KPO4 HK2PO4) - hydrocarbon buffer (CO2 + H2O = HCO3- + H+) - hemoglobin buffer Henderson - Hasselbach formula Immunologic defense - the body must defend itself from microbes and foreign proteins from the environment - two kinds of immunity : - unspecific inborn immunity - specific acquired immunity Unspecific defense phagocytes - neutrophils and monocytes - bacteria enters body tissue - phagocytes are attracted by chemical substances(migration) - surrounding and ingesting by phagocytosis - increased blood flow + increased capillary permeability for proteins = inflammation Specific defense lymphocytes T - 70 % B - 15% NK - 15% - first contact with antigen activates both types of lymphocytes - activated B - lymphocytes multiply giving rise to: - memory cells - store information about antigens so production of the antibodies starts faster during next contact with the same antigen - plasma cells - specialized in producing immunoglobulins (antibodies) - each antigen has its own immunoglobulin T- lymphocytes - release cytokines that activate B-lymphocytes - directly kill cells infected by viruses NK - natural killers - destroy cancer (neoplastic) cells and cells infected by viruses