Microbiology Chapter 20.txt

  1. Components of Blood
    • Hematocrit
    • Plasma 55%, has clotting factors
    • Buffy coat < 1%, white blood cells
    • Red blood cells 45%
  2. Plasma
    • Get from spinning blood
    • Has clotting factors
    • Plasma is serum that contains clotting agents
  3. Serum
    • Naturally separates from blotted blood
    • No clotting factors
  4. Serum is the fluid part of blood, containing:
    • minerals
    • salts
    • proteins, etc.
  5. Percentage of blood occupied by cells
    • female normal range
    • 38 - 46% (average of 42%)
    • male normal range
    • 40 - 54% (average of 46%)
  6. Anemia
    not enough RBCs or not enough hemoglobin
  7. Polycythemia
    • too many RBCs (over 65%)
    • dehydration, tissue hypoxia, blood doping in athletes
  8. Erythrocytes
    Red blood cells
  9. Leukocytes
    White blood cells
  10. Thrombocytes
  11. Blood Proteins
    • Clotting factors: fibrinogen
    • Globulins: immunoglobulin (Antibodies)
    • Albumin: adds osmotic pressure
  12. Formed Elements of Blood
    • Red blood cells ( erythrocytes )
    • White blood cells ( leukocytes )
    • Platelets (thrombocytes)
  13. granular leukocytes
    • neutrophils
    • eosinophils
    • basophils
    • agranular leukocytes
    • lymphocytes = T cells, B cells, and natural killer cells
    • monocytes
  14. Platelets
    • Special cell fragments
    • Thrombocytes
  15. Leukocytes
    • White blood cells
    • Produced in the bone marrow
  16. Neutrophils
    • 65%
    • Polymorphonuclear leukocytes [PMNs]
    • Phagocytes
    • Live about 12 hours
    • Leave the cardiovascular system
    • Eat foreign particles
  17. Eosinophils
    • 2%
    • Orangish with granules
    • Heparin
    • Keeps basophiils in line with anti-histamine
    • Contain toxic compounds to defend against multicellular parasites
  18. Basophils
    • 1%
    • Small, dark blue with darker blue granules
    • Heparin: prevents clotting
    • Histamines: dilatation
    • 1st to site of injury thru the capillaries
    • Prevents clotting and increases blood flow to clean out wound and bring leukocytes
    • Similar to mast cells
    • Acting in allergic reactions
    • Agranular leukocytes
    • Monocytes
    • Lymphocytes
  19. Monocytes
    • 5-10%
    • Phagocytes that mature into macrophages in tissue
    • Can leave the CV, called macrophage when wondering around the body
  20. Lymphocytes
    • Specific immunity
    • T-Cells: cell mediated immunity
    • B-Cells: humoral immunity (Antibodies)
    • Move to the lymph nodes after maturation
    • Natural killer (NK) cells destroy virus-infected and abnormal cells
    • B lymphocytes and T lymphocytes are involved in acquired immunity
  21. Dendritic cells
    • Are found in the skin and other points of pathogen origin
    • They are involved in acquired immunity
  22. Lymphatic system
    • One way
    • No pump
    • Contains lymph veins and lymph nodes
  23. Lymph nodes
    • Are not evenly spaced
    • Found in heavy concentration in areas where appendages attach to the trunk
    • Groin
    • Armpits
    • Neck
    • There is a maze in the lymph node that the lymph moves thru. Foreign matter in this maze attracts T cells and B cells.
  24. Lymph
    Is the clear fluid surrounding tissue cells and filling intercellular spaces
  25. The lymphatic system maintains and distributes
  26. The primary lymphoid tissues are
    The thymus and bone marrow
  27. The secondary lymphoid tissues are
    The spleen and lymph nodes
  28. The spleen contains cells that
    Monitor and fight infectious microbes
  29. The lymph nodes contain
    Phagocytes and lymphocytes
  30. Structure of a lymph node
    • Afferent lymphatic vessels
    • Germinal center
    • Outer cortex (B cells, macrophages, and dendritic cells)
    • Cortex (upper part of B cells and dendritic cells)
    • Medulla (base of B cells, T cells and dendritic cells)
    • Efferent lymphatic vessel
    • Artery
    • Vein
    • Paracortex (upper part of T cells and dendritic cells)
  31. Afferent lymphatic vessels
    Bring lymph into lymph nodes
  32. Efferent lymph vessels
    Take lymph out of lymph nodes
  33. Functions of the lymphatic system
    • Fluid and solute return to blood
    • Lipid transport from digestive system to circulatory system
    • Produce, maintain, and distribute lymphocytes for defense
  34. Innate immunity
    Nonspecific resistance
  35. Cytokines
    • Acquired immunity (specific resistance)
    • Chemical signals sent by many immune cells to tissues involved with initiating acquired immunity
  36. Innate immunity (nonspecific resistance) is genetically-encoded to recognize:
    • Common pathogenic features
    • Foreign substances
  37. Acquired immunity (specific resistance) involves production of:
    • Lymphocytes
    • Antibodies specific to the pathogen causing infection
  38. Nonspecific Resistance
    • Species Immunity
    • Racial Immunities
    • Mechanical and chemical barriers
    • Phagocytosis
  39. Mechanical and chemical barriers to disease
    • Skin and skin penetration
    • Mucous membranes
    • Acidity of stomach and vagina
    • Bile
    • Lysozyme
    • Interferon
  40. Langerhans cells
    If a pathogen is detected by Langerhans cells, they phagocytize it and induce an acquired immune response
  41. Mucous membrane cells
    Produce mucus to trap microbes
  42. Lactobacillus in the human vagina
    Decrease the pH, which resists infection
  43. The low pH in the stomach
    Destroys most pathogens
  44. Defensins
    Antimicrobial peptides found in various bodily secretions
  45. Lysozyme
    • Found in tears, sweat, and saliva
    • Lyses gram-positive bacterial cells
  46. Interferons are cytokines that trigger:
    • Macrophage activation
    • Production of substances to interfere with RNA viral reproduction
  47. The normal microbiota of the body
    Out compete pathogens for nutrients and attachment sites
  48. Phagocytosis
    • Cell eating
    • A nonspecific defense mechanism to clear microbes from infected tissues
    • Capture and digestion of foreign particles
    • Second line of defense
  49. Phagocytes
    Macrophages and neutrophils
  50. Chemokines
    Cytokines that attract macrophages and neutrophils to infected tissues
  51. Opsonins
    Attach to microbes to increase the ability of phagocytes to adhere (opsonization)
  52. Chemotaxis
    A chemical is released by inflamed cells that attracts macrophages and neutophils
  53. Opsonization
    • Similar to chemotaxis
    • A chemical is released by inflamed cells that attracts macrophages and neutophils
  54. Phagocytized microbes are held in a
    • Phagosome
    • The phagosome is acidified, killing or inactivating the pathogen
  55. Phagosomes also fuse with
    • Lysosomes (phagolysosome)
    • Enzymes and other products kill and digest the pathogen
  56. Inflammation
    • Rubor: red
    • Calor: heat
    • Tumor: swelling
    • Dolor: pain
  57. Fever
    Heat body up so virus or bacteria doesn't want to live in us
  58. Natural killer cells
    Destroy invading organisms
  59. Complement
    • 30 known proteins
    • Is inactive until G- or enveloped viruses are detected
    • Becomes active when a phagocyte starts to eat bacteria or virus
    • Eventually causes lysis
  60. Low to moderate fever supports the immune system by:
    • Inhibiting rapid microbial growth
    • Encouraging rapid tissue repair
    • Heightening phagocytosis
  61. Pyrogens are cytokines produced by:
    • Some leukocytes
    • Fragments from pathogens
    • They affect the hypothalamus, causing elevated body temperature
  62. If a temperature rises above 105�F in an adult,
    • Host metabolic inhibition can occur
    • This can cause convulsions and death
  63. Natural killer cells
    • Defensive lymphocytes
    • When activated, they produce cytokines that trigger response by macrophages and other cells
  64. Natural killer cells are formed in the bone marrow, and migrate to:
    • tonsils
    • lymph nodes
    • spleen
  65. Natural killer cells move into blood and lymph where they kill:
    • cancer cells
    • virus-infected cells
  66. MHC
    • Major histocompatibility complex
    • Like a GUID
    • Complex protein on the surface of the cell
    • They are a marker that tells who a cell belongs to.
    • Killer cells check to make sure things running thru the lymph nodes belong to self by looking at the MHC
  67. What do killer cells release if cells are not recognized as self?
    Perforin and granzymes
  68. Complement Marks
    Pathogens for Destruction
  69. Complement is a series
    Of proteins that circulate in the bloodstream
  70. Complement Classical pathway
    They activate in the presence of microbes
  71. In the Complement Classical pathway
    Antibody-microbe complexes activate complement proteins that activate C3 convertase
  72. In the Complement Alternative pathways
    The complement protein C3 binds to the pathogen cell surface to activate C3 convertase

    C3 activation
  73. Complement pathways
    Both Classical and Alternative cascade activation 30 proteins that results in lysis of bacteria (G-) or enveloped viruses
  74. Phagocytosis works with complements to
    Lyse/rupture the invader
  75. Complement actions
    • Inflammatory response
    • Increased phagocytosis
    • Membrane attack complexes
Card Set
Microbiology Chapter 20.txt
Microbiology Chapter 20