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Chapter 29 Blood

Chapter 29 Blood. Composition of Blood. Blood is sticky Color varies from scarlet to dark red The pH of blood is 7.35–7.45 Temperature is 38  C Average volume: 5–6 L for males, and 4–5 L for females. Composition of Blood.

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Chapter 29 Blood

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  1. Chapter 29 Blood

  2. Composition of Blood • Blood is sticky • Color varies from scarlet to dark red • The pH of blood is 7.35–7.45 • Temperature is 38C • Average volume: 5–6 L for males, and 4–5 L for females

  3. Composition of Blood • It is composed of liquid plasma and formed elements • Formed elements include: • Erythrocytes, or red blood cells (RBCs) • Leukocytes, or white blood cells (WBCs) • Platelets

  4. Blood Plasma - Matrix • Blood plasma contains over 100 solutes, including: • Water – 90% • Proteins – albumin, globulins, clotting proteins, and others • Organic nutrients – glucose, carbohydrates, amino acids • Electrolytes – sodium, potassium, calcium, chloride, bicarbonate • Respiratory gases – oxygen and carbon dioxide

  5. Components of Whole Blood Figure 17.1

  6. Erythrocytes (RBCs) • Biconcave discs, anucleate, essentially no organelles • Filled with hemoglobin (Hb), a protein that functions in gas transport • Red or pink • 4.5million to 5.0 million cells/mm3 • Life span – 100 to 120 days

  7. Erythrocytes (RBCs) Figure 17.3

  8. Components of Whole Blood Figure 17.2

  9. Leukocytes (WBCs) • 4000-11000 cells/mm3 • Nucleated • Diapedesis • Divided into 2 groups: • Granulocytesandagranulocytes

  10. Granulocytes • Granulocytes – neutrophils, eosinophils, and basophils • Contain cytoplasmic granules that stain specifically (acidic, basic, or both) with Wright’s stain • Are larger and usually shorter-lived than RBCs • Have lobed nuclei

  11. Neutrophils • Neutrophils have two types of granules that: • Take up both acidic and basic dyes • Give the cytoplasm a lilac color • Neutrophils are our first body’s defense • Increase in bacterial infections • 40% - 70% of all WBCs • Nucleus with 3 to 7 lobes

  12. Eosinophils • Eosinophils account for 1–4% of WBCs • Have red-staining, bilobed nuclei connected via a broad band of nuclear material • Have red to crimson (acidophilic) large, coarse, lysosome-like granules • Lead the body’s counterattack against parasitic worms. Increased in allergic patients • Lessen the severity of allergies by phagocytizing immune complexes

  13. Basophils • Account for 0.5% of WBCs and: • Have U- or S-shaped nuclei with two or three conspicuous constrictions • Are functionally similar to mast cells • Have large, purplish-black (basophilic) granules that contain histamine. • Mediates inflammatory reactions

  14. Agranulocytes • Agranulocytes – lymphocytes and monocytes: • Lack visible cytoplasmic granules • Are similar structurally, but are functionally distinct and unrelated cell types • Have spherical (lymphocytes) or kidney-shaped (monocytes) nuclei

  15. Lymphocytes • Account for 25% or more of WBCs and: • Have large, dark-purple, circular nuclei with a thin rim of blue cytoplasm • Responsible for immunologic responses • Smallest type of leukocytes • There are two types of lymphocytes: T cells and B cells • T cells function in the immune response • B cells produce antibodies

  16. Monocytes • Monocytes account for 4–8% of leukocytes • They are the largest leukocytes • They have abundant pale-blue cytoplasms • They have purple-staining, U- or kidney-shaped nuclei • They leave the circulation, enter tissue, and differentiate into macrophages • Increases in chronic infections

  17. Leukocytes Figure 17.10

  18. Platelets • Platelets are fragments of megakaryocytes with a blue-purple color • Irregular shape • 250,000 - 500,000/mm3 • Platelets function in the clotting mechanism by forming a temporary plug that helps seal breaks in blood vessels

  19. Hematologic Tests • Total WBCs count • Leukocytosis • Leukopenia • Leukemia • Total RBCs count • Polycythemia • Anemia

  20. Hematologic Tests • Differential WBCs count • Hematocrit or packed cell volume (PVC) • Obtained by centrifuging the whole blood • Normal male: 47 • Normal female: 42 • Hemoglobin concentration • Male normal value: 13-18g/100ml of blood • Female normal value: 12-16g/100ml of blood

  21. Hematologic Tests • Sedimentation rate • It is the speed at which RBCs settle to the bottom of a vertical tube • Adult normal value: 0 to 6 mm/hr • It is increased in anemia, infections, tissue necrosis, pregnancy • It is decreased in polycythemia

  22. Hematologic Tests • Bleeding time • Measurement of how long a bleeding lasts • It tests the health of the platelets • Normal rate: 0 to 5 minutes (or 2 to 7) depending on the method used • Coagulation time • Normal value:2 to 6 minutes • It tests the coagulation factors

  23. Hematologic Tests • Steps of coagulation: • Injury • Release of RF and PF3 by the tissue • Trigger of the cascade • Conversion of prothrombin into thrombin • Conversion of fibrinogen to fibrin • Clot formation

  24. Hematologic Tests – blood typing • RBC membranes have glycoprotein antigens on their external surfaces • These antigens are: • Unique to the individual • Recognized as foreign if transfused into another individual • Promoters of agglutination and are referred to as agglutinogens • Presence or absence of these antigens is used to classify blood groups

  25. Blood Groups • The antigens of the ABO and Rh blood groups cause vigorous transfusion reactions when they are improperly transfused • Other blood groups (M, N, Dufy, Kell, and Lewis) are mainly used for legalities • Antibodies are also called agglutinins

  26. ABO Blood Groups • The ABO blood groups consists of: • Type A blood: • Has antigens A on the surface of their RBCs • Has antibodies anti-B in their plasma • Type B blood: • Has antigens B on the surface of their RBCs • Has antibodies anti-A in their plasma

  27. ABO Blood Groups • Type AB blood: • Has both A and B antigens on the surface of their RBCs • Has no antibodies in their plasma • Type O blood: • Has no antigens on the surface of their RBCs • Has anti-A and anti-B in their plasma

  28. ABO Blood Groups Table 17.4

  29. Rh Blood Groups • There are eight different Rh agglutinogens, three of which (C, D, and E) are common • Presence of the Rh agglutinogens on RBCs is indicated as Rh+ • Anti-Rh antibodies are not spontaneously formed in Rh– individuals • However, if an Rh– individual receives Rh+ blood, anti-Rh antibodies form • A second exposure to Rh+ blood will result in a typical transfusion reaction

  30. Blood Typing • When serum containing anti-A or anti-B agglutinins is added to blood, agglutination will occur between the agglutinin and the corresponding agglutinogens • Positive reactions indicate agglutination

  31. Blood Typing

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