immune system.txt

  1. utilizes molecules & immune cells to keep body safe from invading organisms, cancer cells & transplanted tissue; not comprised of organs but is a functional system:
    immune system
  2. non-specific defense system
    innate
  3. specific defense system
    adaptive
  4. non-specific - external body membranes (skin and mucosae)
    first line of defense
  5. non-specific - antimicrobial proteins, phagocytes & other cells; inhibit spread of invaders and inflammation is most important mechanism:
    2nd line of defense
  6. attacks particular foreign substances; takes longer to react than the innate system:
    third line of defense - specific
  7. most abundent white blood cell; become phagocytic on encountering infectious material in tissue:
    neutrophils
  8. mechanism of phagocytosis:
    • 1. adherence of phagocyte to pathogen
    • 2. engulf the particle & form a phagosome vessicle
    • 3. fuse w/a lysosome & form a phagolysosome
    • 4. lysosomal enzymes digest the particle
    • 5. exocytosis of the vessicle removes residual material
  9. inflammatory response:
    • 1. triggered whenever body tissues are injured or infected
    • 2. prevents the spread of damagin agents
    • 3. disposes of cell debris & pathogens
    • 4. sets the stage for repair
  10. large non-specific granular lymphocytes; induce apoptosis in cancer cells & virus-infected cells; secrete potent chemicals that enhance the inflammatory response:
    natural killer (nk) cells
  11. cardinal signs of accute inflammation:
    • 1. redness
    • 2. heat
    • 3. swelling
    • 4. pain
    • 5. sometimes impairment of function
  12. inflammatory mediators:
    • 1. histamine (from mast cells)
    • 2. blood proteins
    • 3. kinins, prostaglandins (PGs), leukotienes & complement
  13. inflammatory chemicals cause:
    • 1. dilation of arterioles, resulting in hypermia (blood congestion), causes redness & heat
    • 2. increased permeability of local capillaries & edema
  14. fluid that contains proteins, clotting factors & antibodies:
    exudate
  15. functions of the surge of exudate:
    • 1. moves foreign material into lymphatic vessels
    • 2. delivers clotting proteins to form a scaffold for repair & to isolate the area
  16. steps for phagocyte mobilization:
    • 1. leukocytosis: release of neutrophils from bone marrow in response to leukocytosis-inducing factors from injured cells
    • 2. margination: neutrophils cling to the walls of capillaries in the inflamed area
    • 3. diapedesis of neutrophils
    • 4. chemotaxis: inflammatory chemotaxis promote positive chemotaxis of neutrophils
  17. dead or dying neutrophils, broken down tissue cells, living & dead pathogens that fill a severly infected wound:
    pus
  18. sac of pus walled off by collagen fibers, must be drained in order for healing to occur:
    abscess
  19. when a macrophage engulfs an organism that cannot be broken down:
    infectious granuloma (a person can harbor an infection for years & if the immune system is ever compromised the infection can activate & cause disease)
  20. attack microorganisms directly; hinder microorganisms ability to reproduce:
    interferons & complement proteins
  21. anti-viral, reduce inflammation, activate macrophages & mobilize Natural Killer cells:
    interferons
  22. amplifies all aspects of the inflammatory response; kills bacteria & certian other cell types by cell lysis; enhances both nonspecific and specific defenses:
    complement proteins
  23. systemic response to invading microorganisms; leukocytes & macrophages exposed to foreign substances secrete pyrogens (reset the body's thermostat upward):
    fever
  24. benefits of moderate fever:
    • 1. causes the liver & spleen to sequester iron & zinc (needed by microorganisms)
    • 2. increases metabolic rate, which speeds up repair
  25. antibody-mediated immunity:
    humoral
  26. cell-mediated immunity:
    cellular
  27. substances that can mobilize the adaptive defenses & provoke an immune response; most are large, complex molecules not normally found in the body (nonself)
    antigens
  28. antibody generating:
    antigen
  29. ability to stimulate proliferation of specific lymphocytes & antibodies:
    immunogenicity
  30. ability to react with products of activate lymphocytes & antibodies released:
    reactivity
  31. incomplete antigens:
    haptens
  32. small molecules; not immunogenic by themselves; are immunogenic when attached to body proteins; cause the immune system to mount a harmful attack:
    haptens ex (poison ivy, animal dander, detergents & cosmetics)
  33. protein molecules (self antigens) on the surface of cells; antigenic to others in transfusions or grafts; are unique to an individual:
    self-antigens (MHC proteins)
  34. able to recognize & bind to a specific antigen:
    immunocompetence
  35. unresponsive to self antigens so that it doesn't attack it's own cells:
    self-tolerance
  36. selects T cells capable of binding to self-MHC proteins (MHC restriction):
    positive selection
  37. prompts apoptosis of T cells that bind to self-antigens displayed by self-MHC; ensures self-tolerance (only 2% make it to maturity)
    negative selection
  38. engulf antigens; present fragments of antigens to be recognized by T cells:
    antigen-presenting cells (APCs)
  39. major types of APCs:
    • 1. dendritic cells in connective tissues & epidermis
    • 2. macrophages in connective tissues & lymphoid organs
    • 3. B cells
  40. uses lymphocytes, APCs & specific molecules to identify & destroy nonself substances; depends upon the ability of its cells to recognize antigens by binding to them & communicate w/one another so that the whole system mounts a specific response:
    adaptive immunity
  41. 1st encounter between an antigen & a naive immunocompetent lymphocyte; usually occurs in spleen or lymph node; if lymphocyte is a B cell the antigen provokes a humoral (antibody) immune response & antibodies are produced:
    humoral immunity response
  42. B cell is activated when antigens bind to its surface receptors & cross-link them; receptor-mediated endocytosis of cross-linked antigen-receptor complexes occurs; stimulated B cells grows to form a clone of identical cells bearing the same antigen-specific receptors:
    clonal selection
  43. clone cells that don't become plasma cells become memory cells; what do they do:
    • provide immunological memory
    • mount an immediate response to future exposures of the same antigen
  44. occurs on the 1st exposure to a specific antigen; lag period is 3-6 days; peak levels of plasma antibody are reached in 10 days; antibody levels then decline:
    primary immune response
  45. occurs on re-exposure to same antigen; sensitized memory cells respond w/i hours; antibody levels peak in 2-3 days at much higher levels; antibodies bind w/greater affinity; antibody level can remain high for weeks to months:
    secondary immune response
  46. occurs when B cells encounter antigens & produce specific antibodies against them:
    active humoral immunity
  47. response to a bacterial or viral infection:
    naturally acquired active humoral immunity
  48. response to a vaccine of dead or attenuated pathogens:
    artificially acquired active humoral immunity
  49. spare us the symptoms of the primary response; provide antigenic determinants that are immunogenic & reactive; target only 2 type of helper T cell, so fail to fully establish cellular immunological memory:
    • vaccines
    • ;
    • B cells aren't challenged by antigens; immunological memory doesn't occur:
    • passive humoral immunity
  50. antibodies delivered to a fetus via the placenta or to infant though milk:
    naturally acquired passive humoral immunity
  51. injection of serum, such as gamma globulin (protection is immediate but ends when antibodies naturally degrade in the body:
    artificially acquired passive humoral immunity
  52. first antibody released; potent agglutinating agent; readily fixes & activates complement
    IgM
  53. monomer or dimer; in mucus and other secretions; helps prevent entry of pathogens:
    IgA
  54. monomer attached to the surface of B cells; functions as a B cell receptor:
    IgD
  55. monomer; 75-85% of antibodies in plasma; from secondary to late primary respones; crosses the placental barrier:
    IgG
  56. monomer active in some allergies & parasitic infections; causes mast cells & basophils to release histamine:
    IgE
  57. defensive mechanisms used by antibodies:
    • 1. neutralization & agglutination (2 most important)
    • 2. precipitation & complement fixation
  58. "plan" of antibody function:
    • Precipitation
    • Lysis (by complement)
    • Agglutination
    • Neutralization
  59. used in pregnancy, STD and rabies test, research and cancer treatment:
    monoclonal antibodies ( commercially prepared pure antibody); produced indefinitely & have the ability to produce a single type of antibody
  60. becomes helper T cells when activated (call for help/helper cells):
    CD4
  61. become cytotoxic T cells that destroy cells harboring foreign antigens (destroyer cells):
    CD8
  62. two types of MHC proteins are important to T cell activation:
    • Class I MHC
    • Class II MHC (both are synthesized at the ER and bind to peptide fragments)
  63. displayed by all cells except RBCs; interact w/CD8 cells:
    Class I MHC proteins
  64. displayed by antigen presenting cells (APC), dendritic cells, macrophages and B cells; interact w/CD4 cells:
    Class II MHC proteins
  65. endogenous (from within) antigen is a self-antigen in a normal cell; a nonself antigen in an infected or abnormal cell; informs cytotoxic T cells of the presence of microorganisms hiding in cells:
    Class I MHC proteins
  66. bind with fragments of exogenous antigens that have been engulfed & broken down in a phagolysosome; recognized by helper T cells:
    Class II MHC proteins
  67. directly attack & kill other cells; activated T cells circulate in blood & lymph & lymphoid organs in search of body cells displaying antigen they recognize:
    roles of cytotoxic cells
  68. targets of cytotoxic cells:
    • 1. virus - infected cells
    • 2. cells w/intracellular bacteria or parasites
    • 3. cancer cells
    • 4. foreign cells (transfusions or transplants)
  69. from one body site to another in the same person:
    autograft
  70. between identical twins:
    isografts
  71. between individuals who aren't identical twins:
    Allografts
  72. from another animal species:
    Xenografts
  73. removing the patients bone marrow & transplanting the donors red marrow into the patient; allows the organ to be treated as self instead of foreign; similiar method has been shown to cure HIV infection in 1 case in Europe:
    Chimeric Immune System
  74. congential & acquired condition that cause immune cells, phagocytes or complement to behave abnormally:
    immunodeficiencies
  75. genetic defect; marked deficit in B & T cells; abnormalities in interleukin receptors; defective adenosine deaminase enzyme (ADA); is fatal if untreated:
    SCID (severe combined immunodeficiency syndrome
  76. an acquired immunodeficiency; cancer of the B cells; leads to immunodeficiency by depressing lymph node cells:
    Hodgkins Disease
  77. cripples the immune system by interfering w/ the activity of helper T cells; characterized by severe weight loss, night sweats & swollen lymph nodes; opportunistic infections occur, including pneumocystis pneumonia & Kaposi's sacroma:
    AIDS (acquired immune deficiency syndrome)
  78. immune system loses the ability to distinguish self from foreign; production of autoantibodies & sensitized TC cells that destroy body tissues:
    Autoimmune diseases ex(mulitple sclerosis, graves disease, type I diabetes)
  79. destroys myelin sheath on neural tissue:
    multiple sclerosis
  80. impaired communication between nerves & skeletal muscle:
    myasthenia gravis
  81. prompts excessive thryoxine produced by thyroid:
    graves disease
  82. destroys beta cells of the pancreas that produce insulin:
    type I diabetes
  83. systemic disease that destroys the kidney, heart, lungs and skin:
    lupus
  84. severe impairment of renal function:
    glomerulonephritis
  85. destroys joints of the body:
    rheumatoid arthritis
  86. mechanisms of autoimmune diseases:
    • 1. foreign antigens may resemble self-antigens
    • 2. new self-antigens may appear
    • 3. release of novel self-antigens by trauma of a barrier
  87. immune responses to a perceived threat; causes tissue damage; antibodies cause immediate & subcute hypersensitivites; T cells cause delayed hypersensitivity:
    hypersensitivites
Author
Anonymous
ID
142365
Card Set
immune system.txt
Description
immune system
Updated