Chapter 14 - Blood


Published on

Published in: Health & Medicine, Business

Chapter 14 - Blood

  1. 1. Chapter 14 Blood PowerPoint Presentation to accompany Hole’s Human Anatomy and Physiology, 10 th edition , edited by S.C. Wache for Biol2064.01
  2. 2. You are responsible for the content of the following figures and topics: Fig. 14.1 – Blood. Fig. 14.2 - hematocrit or Percent packed RBC volume. Fig. 14.5 - Blood originates from red bone marrow. Fig. 14.3 - Blood cells. WBC develop into 3 branches. Fig. 14.14 - WBC can pass through the simple epithelia of vessels by diapedesis, RBC cannot. Fig. 14.16 - Blood composition. Read TB, p.527, on hemostasis. Fig. 14. 19, Tab. 14.10 - Damaged tissues trigger the extrinsic mechanism. Read TB, p.533, on antigens and antibodies of blood groups. Fig. 14.21, 14.22 – Key-and-Lock interaction of Antigens and Antibodies. Tab. 14.13 - Study the antibodies each blood type carries in their plasma. Tab. 14.14 - Permissible Donor Blood Types. Fig. 14.23 - incompatibility with the Rh antigen also called antigen D.
  3. 3. Blood Volume and Composition <ul><li>Blood volume is 8% of body weight </li></ul><ul><li>Average adult has 5 liters of blood </li></ul><ul><li>Blood is 45% cells </li></ul><ul><ul><li>This is also known as the hematocrit or percent packed cell volume </li></ul></ul><ul><ul><li>99% are red blood cells, remainder white blood cells and blood platelets </li></ul></ul><ul><ul><li>The hematocrit is an indicator of anemia, polycythemia, and other conditions. </li></ul></ul><ul><li>Blood is 55% plasma </li></ul><ul><ul><li>water, amino acids, proteins, carbohydrates, lipids, vitamins, hormones, electrolytes, wastes </li></ul></ul>
  4. 4. Fig. 14.3
  5. 5. Red Blood Cell Synthesis and Aging <ul><li>Erythrocytes or RBC are synthesized in response to erythropoetin (kidney hormone) </li></ul><ul><li>The mature cells lack nuclei and are small, biconcave disks. They no longer can divide. </li></ul><ul><li>Cells consist 1/3 of hemoglobin (Hb) , the protein that carries oxygen in blood. </li></ul><ul><li>RBC lack mitochondria and produce ATP through glycolysis only </li></ul>Red Blood Cell Destruction <ul><li>Damaged or worn cells rupture in the spleen or liver. </li></ul><ul><li>In the spleen or liver, macrophages phagocytize and destroy cells. </li></ul><ul><li>Hb is broken down into globin and heme which decomposes into biliverdin . </li></ul><ul><li>The heme group has a central iron element to which oxygen binds. </li></ul><ul><li>Biliverdin is converted to bilirubin and excreted in bile via the gallbladder . </li></ul><ul><li>Iron is carried on transferrin to the liver were it is stored as ferritin. </li></ul>
  6. 6. Fig. 14.8 Note that, in muscle, myoglobin (Mb) binds oxygen. Mb consists of only 1 protein chain. Note the 4 protein chains that make up 1 molecule of Hb.
  7. 7. Erythropoiesis – RBC production <ul><li>Red blood cells (RBC) are called erythrocytes. </li></ul><ul><li>They are produced in red bone marrow. </li></ul><ul><li>Average life span is 120 days. </li></ul><ul><li>When oxygen concentrations in the blood are low , erythropoietin is released from the kidney . </li></ul><ul><li>Erythropoietin operates in a negative feedback mechanism to maintain RBC homeostasis . </li></ul>Required Dietary Factors <ul><li>Vitamin B12 - required for DNA synthesis </li></ul><ul><ul><ul><li> - intrinsic factor necessary for absorption </li></ul></ul></ul><ul><li>Folic acid - required for DNA synthesis </li></ul><ul><li>Iron - required for hemoglobin synthesis </li></ul><ul><li>Vitamin C - increases absorption of iron </li></ul>
  8. 8. Fig. 14.6
  9. 9. Fig. 14.7 NORMAL BLOOD ANEMIC BLOOD ane·mia : a condition in which the blood is deficient in red blood cells, in hemoglobin, or in total volume – see APLASTIC ANEMIA, HYPERCHROMIC ANEMIA, HYPOCHROMIC ANEMIA, MEGALOBLASTIC ANEMIA, MICROCYTIC ANEMIA, PERNICIOUS ANEMIA, SICKLE-CELL ANEMIA; compare OLIGOCYTHEMIA
  10. 10. White Blood Cells <ul><li>White Blood Cells (WBC) are called leukocytes . </li></ul><ul><li>They protect against disease. </li></ul><ul><li>Granulocytes: granular cytoplasm; neutrophils, eosinophils, basophils </li></ul><ul><li>Agranulocytes: lack cytoplasmic granules; monocytes, lymphocytes </li></ul>Blood Platelets <ul><li>Thrombocytes </li></ul><ul><li>Arise from megakaryocytes in the red bone marrow </li></ul><ul><li>Platelets are small and lack a nucleus </li></ul><ul><li>Help repair broken blood vessels </li></ul><ul><li>Release serotonin </li></ul>
  11. 11. Neutrophils ( Fig. 14.9) <ul><li>Granules stain light purple in acid-base combination stains </li></ul><ul><li>First white blood cells that arrive at place of infection </li></ul><ul><li>They constitute 54% to 62% of the leukocytes. </li></ul><ul><li>Older neutrophils are called segs (segments) or polymorph nuclear leukocytes due to nuclear appearance </li></ul><ul><li>Younger neutrophils are called bands </li></ul>
  12. 13. Eosinophils (Fig. 14.10) <ul><li>Contain coarse deep red staining granules </li></ul><ul><li>Nucleus has two lobes </li></ul><ul><li>Active during moderate allergic reactions </li></ul><ul><li>Defend against parasitic worm infection </li></ul><ul><li>Constitute 1% to 3% of leukocytes </li></ul>
  13. 15. Basophils (Fig. 14.11) <ul><li>Granules stain deep blue in basic stain </li></ul><ul><li>Nuclei have two lobes </li></ul><ul><li>Migrate to damaged tissue </li></ul><ul><li>Release histamine to promote inflammation and heparin to inhibit blood clotting </li></ul><ul><li>Constitute less than 1% of leukocytes </li></ul>
  14. 17. Agranulocytes (Figs. 14.12, 14.13) <ul><li>Monocytes: largest cells; leave bloodstream and become macrophages; 3% to 9% of the leukocytes </li></ul><ul><li>Lymphocytes: T cells and B cells; important in immunity and antibody production; 35% to 33% of leukocytes </li></ul>
  15. 18. Movement of Leukocytes through Epithelia <ul><li>Protect against infection: phagocytize bacteria; produce proteins that destroy foreign particles </li></ul><ul><li>Diapedesis: leukocytes can squeeze between cells and leave the circulation </li></ul>Fig. 14.14
  16. 19. Infection
  17. 20. Blood Plasma <ul><li>92% water, Plasma proteins, Gases and nutrients </li></ul><ul><li>nitrogen containing molecules other than proteins: amino acids, urea, uric acid, creatine, creatinine </li></ul><ul><li>Plasma electrolytes : sodium (Na + ), potassium (K + ), calcium (Ca ++) , magnesium (Mg ++ ), chloride (CL - ), bicarbonate, phosphate, sulfate </li></ul>Plasma Proteins <ul><li>Albumins : 60%; maintain osmotic pressure, bind and transport molecules </li></ul><ul><li>Globulins : 36%; alpha, beta, gamma-globulins </li></ul><ul><li>Fibrinogen : 4%; primary role in blood clotting </li></ul>Blood Gases and Nutrients <ul><li>Blood gases: oxygen and carbon dioxide </li></ul><ul><li>Nutrients: </li></ul><ul><li>amino acids, simple sugars, nucleotides, lipids; </li></ul><ul><li>lipids include triglycerides, phospholipids, cholesterol transported as lipoproteins </li></ul><ul><li>(chylomicrons, VLDL, LDL, HDL) </li></ul>
  18. 21. Fig. 14.16
  19. 22. Hemostasis – Platelet Plug Formation <ul><li>Stoppage of bleeding to prevent blood loss </li></ul><ul><li>Blood vessel spasm: vasospasm due to smooth muscle contraction; direct stimulation of vessel wall and pain reflexes </li></ul>Blood Coagulation: Fibrinogen Fibrin <ul><li>Complex cascade of events </li></ul><ul><li>Utilizes clotting factors </li></ul><ul><li>Vitamin K and calcium is necessary for clotting factors </li></ul><ul><li>Major event is conversion of soluble plasma protein fibrinogen to insoluble treads of fibrin </li></ul>Two ways to stop blood flow: hemostasis and coagulation
  20. 23. Fig. 14.17
  21. 24. Fig. 14.19
  22. 25. Extrinsic Clotting Mechanism <ul><li>Triggered when blood contacts damaged blood vessel wall or tissue outside blood vessels; damaged tissue releases thromboplastin. </li></ul><ul><li>Thromboplastin activates clotting cascade involving reactions that require calcium and leading to the release of prothrombin. </li></ul><ul><li>Prothrombin is converted into thrombin. </li></ul><ul><li>Thrombin converts fibrinogen to fibrin </li></ul><ul><li>Fibrin threads stick to exposed damaged blood vessels. </li></ul><ul><li>Meshwork traps blood cells and platelets. This produces a blood clot . </li></ul><ul><li>The amount of prothrombin activator is proportional to the degree of tissue damage. </li></ul><ul><li>Blood clotting is self-initiating, a positive feedback system . </li></ul>Intrinsic Clotting Mechanism <ul><li>All components found within blood , not outside the vessel !!! </li></ul><ul><li>Activation of Hageman Factor initiates intrinsic clotting </li></ul><ul><li>Cascade of activation in the presence of calcium produces prothrombin activator </li></ul><ul><li>Prothrombin and fibrin are formed as in the extrinsic pathway </li></ul>
  23. 26. Clot Physiology <ul><li>Blood flow keeps thrombin concentration low, that is, as blood thickens and blood flow decreases, thus increases the risk of thrombus formation </li></ul><ul><li>Thrombus: a stationary clot abnormally forming in a vessel </li></ul><ul><li>Embolus : a dislodged clot carried by the bloodstream; Embolism occurs when the embolus blocks blood flow </li></ul>Fate of Blood Clots <ul><li>When blood clots dry out and retract inward they pull torn vessel ends together. Serum is squeezed out. </li></ul><ul><li>Platelet-derived growth factor (PDGF) repairs vessel walls. </li></ul><ul><li>Plasminogen is absorbed by fibrin. Plasminogen activator converts plasminogen to plasmin . Plasmin digests the clot . </li></ul>Prevention of Coagulation <ul><li>Prostacyclin from endothelial cells inhibits platelet aggregation. </li></ul><ul><li>Antithrombin inactivates thrombin. </li></ul><ul><li>Heparin from basophils interferes with the formation of prothrombin activator. </li></ul><ul><li>Note: Plasminogen activator is used together with blood thinners after a stroke ! </li></ul>
  24. 27. Antigens and Antibodies <ul><li>Blood cell compatibility is based on clumping or agglutination </li></ul><ul><li>Transfusion reaction : a reaction between red blood cell antigens = agglutinogens and protein antibodies = agglutinins in the plasma leading to agglutination and hemolysis and blockage of blood flow ! </li></ul><ul><li>Antigens include those of the ABO group and the Rh group </li></ul>ag·glu·ti·na·tion: a reaction in which particles (such as RBC or bacteria); that are suspended in a liquid, collect into clumps especially in response to antiserum added in a serological blood test, that is, as a serological response to a specific antibody. agglutination test: any of several tests based on the ability of a specific serum to cause agglutination of a suitable system and used in the diagnosis of infections, the identification of microorganisms, and in blood typing Agglutination is observed on a blood slide. Note- he·mo·ly·sis: lysis of red blood cells with liberation of hemoglobin.
  25. 28. Fig. 14.22 Donor RBCs: They carry the antigen A. The donor is Blood Type A. Patient Blood: The patient is blood type B and has naturally occurring antibodies called Anti-A. Patient blood after wrong transfusion: The patient blood agglutinates and hemolyses. The patient dies.
  26. 29. Fig. 14.21
  27. 30. <ul><li>ABO blood groups are based on RBC membrane antigens A and B. </li></ul><ul><li>Four possible combinations </li></ul><ul><ul><li>Type A contains antigen A </li></ul></ul><ul><ul><li>Type B contains antigen B </li></ul></ul><ul><ul><li>Type AB contains antigens A and B </li></ul></ul><ul><ul><li>Type O contains no antigens </li></ul></ul>
  28. 31. ABO Blood Group <ul><li>Anti-A and anti-B antibodies are produced when an antigen is absent from the cell membrane </li></ul><ul><ul><li>Type A plasma contains anti-B antibodies </li></ul></ul><ul><ul><li>Type B plasma contains anti-A antibodies </li></ul></ul><ul><ul><li>Type AB plasma contains anti-A and anti-B antibodies, universal recipient </li></ul></ul><ul><ul><li>Type O plasma contains no antibodies, universal donor </li></ul></ul>
  29. 32. Rh Blood Group (Fig. 14.23) <ul><li>Rh positive indicates presence of antigen D, one of the Rh antigens </li></ul><ul><li>Rh negative indicates absence of Antigen D </li></ul><ul><li>Rh antigens, like A and B antigens are inherited and present from birth </li></ul><ul><li>Anti-D antibodies are not produced until after an individual is sensitized to antigen D </li></ul>