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Blood

Blood. 0. 7. Circulatory System Overview. Consists of heart (pump),blood vessels, and blood Picks up nutrients from digestive system Exchanges gases with respiratory system Delivers nutrients and O 2 to every cell Carries CO 2 to lungs for removal

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Blood

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  1. Blood 0 7

  2. Circulatory System Overview Consists of heart (pump),blood vessels, and blood Picks up nutrients from digestive system Exchanges gases with respiratory system Delivers nutrients and O2 to every cell Carries CO2 to lungs for removal Carries wastes and excess water to urinary system Carries metabolic wastes to liver for removal

  3. Figure 7.1 Oxygen intake Elimination of carbon dioxide Food and water intake The Human Body Respiratory system O2 CO2 Nutrients, salt, water Water, salts, metabolic waste Urinary system Digestive system Circulatory system Metabolic waste Transport to and from all cells Elimination of food residues, metabolic wastes Elimination of excess water, salts, metabolic wastes

  4. The Components and Functions of Blood Blood is a specialized connective tissue consisting of: Specialized cells and cell fragments Watery solution of ions, molecules Three primary functions: 1. Transportation of nutrients, waste, hormones 2. Regulation of body temperature, water volume, pH 3. Defense against infections and bleeding

  5. Animation: Blood Right-click and select Play

  6. The Components and Functions of Blood Plasma (makes up 55% of whole blood) Water Electrolytes Proteins (albumins, globulins, clotting proteins) Hormones Gases Nutrients and wastes Formed elements (makes up 45% of whole blood) RBCs WBCs Platelets

  7. Table 7.1

  8. Figure 7.2 Plasma (55%) Whole blood Platelets and WBC (1%) RBC (44%) Blood after being spun in centrifuge. Whole blood. A table-top centrifuge.

  9. Plasma Consists of Water and Dissolved Solutes Plasma: liquid portion of the blood 90% water 10% dissolved solutes Proteins Hormones Ions Amino acids Carbohydrates Vitamins Metabolic wastes

  10. Plasma Consists of Water and Dissolved Solutes Plasma proteins Albumins: maintain osmotic balance with interstitial fluid Globulins: diverse group of proteins Alpha Beta globulins: important transport functions Bind to lipid forming lipoproteins HDL: high density lipoproteins LDL: low density lipoproteins Gamma globulins: antibodies which are part of the body’s defenses against infections Clotting proteins

  11. Red Blood Cells (Erythrocytes) Transport Oxygen and Carbon Dioxide Make up almost half the blood volume 5 million/mm3 Functions: transport oxygen (O2) and carbon dioxide (CO2) Packed with hemoglobin, a protein which transports O2 Hemoglobin molecule includes heme groups which each have iron atoms to which O2 binds Origin: stem cells in the bone marrow Life span: 120 days in humans Control of production: erythropoietin (hormone)

  12. Figure 7.3

  13. Figure 7.4 Polypeptide chain Heme group with iron atom

  14. Hematocrit and Hemoglobin Reflect Oxygen-Carrying Capacity Hematocrit: the percentage of whole blood that consists of red blood cells Men: 43–49% Women: 37–43% Hemoglobin measurement Men: 14–18 gm% Women: 12–14 gm% Low hematocrit or hemoglobin may indicate anemia High hematocrit may be response to high elevation (less O2 available in atmosphere) Very high hematocrit—risky because of increased blood viscosity

  15. Red Blood Cells (RBC’s) Have a Short Life Span Stem cells in bone marrow develop into erythroblasts Erythroblasts fill with hemoglobin, mature into red blood cells, and discard their nucleus and organelles RBC’s live for about 120 days Aged RBC’s are removed by macrophages (large phagocytic cells) in the liver and spleen Iron and amino acids from hemoglobin are recycled Heme (minus the iron), is converted to bilirubin, discarded through digestive tract

  16. Figure 7.5 Stem cells are located in red bone marrow Stem cells multiply and become specialized Mature blood cells Erythrocyte (red blood cell) Erythroblast Nucleus lost Neutrophil Granular leukocytes Eosinophil Myeloblast White blood cells Basophil Stem cell Monoblast Monocyte Agranular leukocytes Lymphocyte Lymphoblast Megakaryocyte Platelets Megakaryoblast

  17. RBC Production Is Regulated by a Hormone RBC number maintained by negative feedback Special cells in kidney monitor O2 availability—secrete hormone erythropoietin (EPO) if O2 levels are low EPO stimulates stem cells in bone marrow—causes increase in red blood cell production Some cases of kidney disease—inadequate EPO secretion—must be supplemented Some athletes have abused EPO by injecting it to increase their red blood cell production May increase viscosity of blood, making the heart work harder to pump it

  18. Figure 7.6 O2 availability Increase Set point Decrease O2-sensitive cells in kidneys respond to a decline in O2 availability by increasing erythropoietin production Increased number of RBCs returns O2 availability to normal Erythropoietin stimulates increased RBC production by stem cells in bone marrow

  19. White Blood Cells (Leukocytes) Defend the Body Arise from division of stem cells in bone marrow Make up 1% of whole blood Functions Protection from infection Regulation of the inflammatory reaction Two general types: Granular: neutrophils, eosinophils, and basophils Agranular: lymphocytes and monocytes

  20. Granular Leukocytes Neutrophils 60% of circulating WBCs First on the scene to fight infection by engulfing microorganisms Eosinophils 2–4% of circulating WBCs Defend against large parasites (worms) Moderate the severity of allergic reactions Basophils 0.5% of circulating WBCs Histamine in granules—role in inflammation and allergic reactions

  21. Agranular Leukocytes Monocytes 5% of circulating WBCs Leave the blood and transform into macrophages Lymphocytes 30% of circulating WBCs Play a large role in the immune response Two types B lymphocytes T lymphocytes

  22. Platelets Are Essential for Blood Clotting Megakaryocytes arise from division of stem cells in bone marrow Megakaryocytes in bone marrow break into fragments called platelets Platelets play an important role in hemostasis If blood vessel is injured, platelets initiate the clotting process Platelets participate in the repair process

  23. Hemostasis: Stopping Blood Loss Three stages 1.Vascular spasm: constriction of blood vessels to reduce blood flow 2.Platelet plug formation: sealing of the ruptured blood vessel 3.Coagulation: formation of a blood clot Blood changes from a liquid to a gel Complex series of reactions involving at least 12 different clotting proteins in the plasma

  24. A Blood Clot Forms Around the Platelet Plug Damage to blood vessels initiates the process Platelets release prothrombin activator Prothrombin activator converts prothrombin (plasma protein) to thrombin (active enzyme) Thrombin converts fibrinogen (soluble plasma protein) to fibrin (insoluble fibers) Mass of fibrin, platelets, trapped RBCs forms blood clot Clot contracts and tightens

  25. Figure 7.8 Red blood cell Vessel injury. Damage to a blood vessel exposes the vessel muscle layers and the tissues to blood. 1 Vascular spasm. The blood vessel contracts, reducing blood flow. 2 Platelets Platelet plug formation. Platelets adhere to each other and to the damaged vessel. 3 Fibrin strands Clot formation. Soluble fibrinogen forms an insoluble mesh of fibrin, trapping RBCs and platelets. 4

  26. Clotting Disorders Bleeding disorder Hemophilia: deficiency of one or more clotting proteins Hemophilia A—lack Factor VIII Today, Factor VIII can be made by genetic engineering to supplement hemophiliacs Some medications interfere with hemostasis Aspirin

  27. Human Blood Types Blood transfusion: administration of blood directly into bloodstream of another person Success depends on matching the blood type of the donor with that of the recipient ABO blood types (A, B, AB, and O) Rh (Rh-positive and Rh-negative)

  28. Human Blood Types Antigen: non-self protein, foreign to the body May be on a cell from another individual or on the cell of an invading microorganism

  29. Human Blood Types • Antibody: a defensive protein made by the body, directed against specific antigens • Antibodies are gamma globulins, proteins found in the plasma • Many antibodies are directed against infectious microbes • Other antibodies may be directed against other antigens, such as those found on the cells of blood received in a blood transfusion • Antibodies may clump and inactivate antigen-bearing cells

  30. Figure 7.11 “Self” surface protein Foreign cell Antigen Antigen-antibody complex Antibody Antibody binds to antigen. Antibodies ignore the “self” surface proteins but bind to the antigen of the foreign cell, forming an antigen-antibody complex. Antigen-antibody complexes clump together. Clumping effectively inactivates the foreign cells.

  31. ABO Blood Typing Is Based On A and B Antigens The antigen on the rbc surface determines the blood type Individuals have A and/or B or neither antigen on their red blood cell surfaces (A, B, AB, or O) Individuals have antibodies against the antigens NOT on their own red blood cells If the recipient of a blood transfusion has antibodies against the donated cells, a severe, possibly fatal reaction may occur

  32. ABO Blood Typing Is Based On A and B Antigens Recipient must not receive cells that they have antibodies against Individual with Type A blood (has anti-B antibodies): can receive A blood or O blood Individual with Type B blood (has anti-A antibodies): can receive B blood or O blood Individual with Type AB blood (has neither antibody type): can receive A, B, AB, or O Individual with Type O blood (has both anti-A and anti-B antibodies): can receive only O blood Type O donor—considered “universal” donor

  33. Figure 7.12 Type O Type AB Type B Type A Antigen A Antigens A and B Neither A nor B antigens Antigen B Red blood cells Plasma antibodies A and B Neither A nor B B A Incidences: 10% 20% 1% 40% 27% 8% 45% 49% 91% 5% 4% 0% U.S. Caucasians U.S. African Americans Native Americans

  34. Rh Blood Typing Is Based On the Rh Factor Rh factor: another antigen found on red blood cell surfaces 85% of Americans are Rh-positive (have the antigen) 15% are Rh-negative These individuals will respond to Rh-positive blood by producing anti-Rh antibodies

  35. Rh Blood Typing Is Based On the Rh Factor Can be a problem when an Rh-negative women is pregnant with an Rh-positive fetus Mother may produce anti-Rh antibodies that cross placenta and damage fetal red blood cells Anti-Rh antibodies from mother cause hemolytic disease of the newborn Rh-positive baby Risk much higher for second and subsequent pregnancies Can be prevented by giving mother Rho-GAM (anti-Rh antibodies) during pregnancy and at delivery

  36. Figure 7.13 Placenta separating from uterus Anti-Rh antibodies Anti-Rh antibodies Anti-Rh antibodies Placenta Umbilical cord Uterus RH RH RH RH RH RH Fetal red blood cells (Rh) Blood flow after pregnancy Maternal red blood cells (Rh) Fetal circulation Fetal circulation Maternal circulation Maternal circulation Maternal circulation When the woman becomes pregnant with her second Rh-positive child, her immune system quickly produces antibodies that attack the fetus’s red blood cells. During pregnancy or more commonly at childbirth, a small amount of fetal blood enters the mother’s circulation. When an Rh-positive man fathers a child by an Rh-negative woman, the fetus may inherit the Rh- positive antigen. Over the next several weeks the woman develops antibodies and an immune memory against the Rh antigen.

  37. Animation: Blood Types Right-click and select Play

  38. Blood Typing and Cross-matching Ensure Blood Compatibility Blood typing Determines ABO and Rh types Procedure involves adding anti-A , anti-B, and anti-Rh antibodies to separate samples of blood cells being tested and observing for agglutination (clumping) Cross-matching involves mixing donor cells with recipient plasma and recipient cells with donor plasma and examining each for agglutination No agglutination in either indicates a “good match”

  39. Figure 7.14 Blood being tested Antibodies Anti-A Anti-B Type A (Contains antigen A) Type B (Contains antigen B) Agglutinated blood Type AB (Contains antigens A and B) Type O (Contains neither A nor B antigens)

  40. Blood Substitutes Why use blood substitutes: Presence of transmissible diseases in donor blood The right type of blood might not always be available Limited storage of whole blood Inability to meet demand for donor blood Two types of oxygen-carrying blood substitutes: Various modified hemoglobins in aqueous solution Hemoglobin must be packaged in some way Perfluorocarbons (PFCs) in aqueous solution can carry more oxygen than whole blood

  41. Blood Disorders Infections Mononucleosis Contagious Epstein-Barr virus infection of lymphocytes Also known as “mono” or “kissing disease” Flu-like symptoms Blood poisoning: bacterial infection of blood Also known as septicemia May develop from infected wounds, burns, urinary tract infections, major dental procedure May be life-threatening Requires antibiotic treatment

  42. Blood Disorders Red blood cells Anemia: reduction in oxygen-carrying capacity due to inadequate number of red blood cells or inadequate hemoglobin Iron-deficiency anemia: caused by inadequate intake or malabsorption of dietary iron Hemorrhagic anemia: caused by blood loss Pernicious anemia: caused by Vitamin B12 deficiency Hemolytic anemia: caused by destruction of red blood cells Anemia due to renal failure Results from inadequate erythropoietin secretion

  43. Blood Disorders White blood cells Leukemia Forms of blood cancer characterized by proliferation of white blood cells May be acute or chronic Treatments may include radiation or chemotherapy to destroy abnormal stem cells followed by bone marrow transplant Multiple myeloma Form of cancer involving the proliferation of plasma cells (type of lymphocyte) in the bone marrow Bone is weakened by the cancer

  44. Blood Disorders Platelets Thrombocytopenia Reduction in platelet number May be caused by viral infection, anemia, leukemia, exposure to radiation, reaction to certain drugs Unusual bruising and bleeding

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