Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Chapter 007

830 views

Published on

Ch 7

Published in: Health & Medicine
  • Be the first to comment

Chapter 007

  1. 1. Chapter 7 Immunity
  2. 2. Immune System  Responsible for body defenses  Nonspecific response (defense) • Examples: phagocytosis, inflammation  Specific response (defense) • Production of specific antibodies against foreign substances •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •2
  3. 3. Components of the Immune System  Lymphoid structures  Lymph nodes  Spleen  Tonsils  Intestinal lymphoid tissue  Lymphatic circulation  Immune cells  Lymphocytes  Macrophages •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •3
  4. 4. Components of the Immune System (Cont.)  Tissues—immune cell development  Bone marrow • Origination of all immune cells •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •4  Thymus • Maturation of T lymphocytes
  5. 5. Structures of the Immune System •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •5
  6. 6. Elements of the Immune System •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •6  Antigens  Self • HLA proteins label cells of the individual. • Immune system ignores self cells.  Non-self • Immune system recognizes specific nonself antigens as foreign. • Development of a specific response to that particular antigen • Memory cells produced to respond quickly to antigen
  7. 7. Antigens (Immunogens)  Usually exogenous substances  Cell surface antigens  Proteins  Polysaccharides  Glycoproteins •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •7
  8. 8. Cells  Macrophages  Initiation of immune response  Develop from monocytes  Part of the mononuclear phagocytotic system  Engulf foreign material  Display antigens of foreign material  Secrete chemicals • Examples: monokines, interleukins  Present throughout the body •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •8
  9. 9. Cells  Lymphocytes  T lymphocytes • From bone marrow stem cells • Further differentiation in thymus • Cell-mediated immunity • Cytotoxic T killer cells • Helper T cells • Memory T cells •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •9
  10. 10. Cells (Cont.)  Lymphocytes  B lymphocytes • Responsible for production of antibodies • Humoral immunity • Mature in bone marrow  Proceed to spleen and lymphoid tissue • Plasma cells  Produce antibodies • B memory cells  Can quickly form clone of plasma cells •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •10
  11. 11. Types of Immunity  Humoral immunity: Antibodies are produced to protect the body.  Cell-mediated immunity (CMI): Lymphocytes are programmed to attack nonself cells to protect the body. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •11
  12. 12. Development of Cellular and Humoral Immunities •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •12
  13. 13. Antibodies and Immunoglobulins •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •13  IgG  Most common in blood  IgM  First to increase in immune response  IgA  In secretions • Tears • Saliva and mucous membranes • Colostrum
  14. 14. Antibodies and Immunoglobulins (Cont.) •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •14  IgE  Allergic response  Causes release of histamine and other chemicals  Results in inflammation  IgD  Attached to B cells  Activates B cells
  15. 15. Review of the Major Components of the Immune System  Major components of the immune system and their function •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •15
  16. 16. Complement System  Activated during immune reactions with IgG or IgM  Group of inactive proteins circulating in blood  C1 to C9  Causes cell damage and further inflammation when activated •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •16
  17. 17. Chemical Mediators  Involved in inflammation and immune reactions  Examples: histamine, interleukins  Variety of functions  Signaling  Causing cellular damage •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •17
  18. 18. Diagnostic Tests  Titer (titre)  Measures levels of serum immunoglobulins  Indirect Coombs’ test  Detects Rh blood incompatibility •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •18  Elisa  Detects HIV antibodies  Used for a number of other diseases  MHC typing  Tissue matching before transplantation procedures
  19. 19. Immunity  Natural immunity  Species-specific  Innate immunity  Gene-specific  Related to ethnicity •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •19
  20. 20. Immunity (Cont.)  Primary response  First exposure to antigen  1 to 2 weeks before antibody titer reaches efficacy  Secondary response  Repeat exposure to the same antigen  More rapid response, with efficacy in 1 to 3 days •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •20
  21. 21. Primary and Secondary Immune Responses •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •21
  22. 22. Immunity  Active natural immunity  Natural exposure to antigen  Development of antibodies  Active artificial immunity  Antigen purposefully introduced to body  Stimulation of antibody production  Immunization  Booster immunization •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •22
  23. 23. Immunity (Cont.)  Passive natural immunity  IgG transferred from mother to fetus: • Across placenta • Through breast milk  Protection of infant for the first few months of life or until weaned  Passive artificial immunity  Injection of antibodies  Short-term protection •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •23
  24. 24. Types of Acquired Immunity •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •24
  25. 25. Tissue and Organ Transplant Rejection  Hyperacute rejection  Immediately after transplantation  Acute rejection  Develops after several weeks  Chronic, late rejection  Occurs after months or years •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •25
  26. 26. Immunosuppression  Reduction of immune response to prevent rejection  Commonly used drugs  Cyclosporine, azathioprine, prednisone  High risk of infection  Caused by immunosuppression  Opportunistic organisms •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •26
  27. 27. Hypersensitivity Reactions  Type I hypersensitivity—allergic reactions  Common • Caused by allergen • Skin rashes • Hay fever  Causative mechanism • Exposure to allergen • Development of IgEs • Mast cells  Complications • Anaphylaxis •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •27
  28. 28. Hypersensitivity Reactions (Cont.)  Type I hypersensitivity–allergic reactions (Cont.)  Hay fever: allergic rhinitis • Nasal mucosa  Food allergies • Digestive tract mucosa  Atopic dermatitis/eczema •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •28 • Skin  Asthma • Bronchial mucosa
  29. 29. Type I Hypersensitivity •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •29
  30. 30. Anaphylaxis: Anaphylactic Shock  Severe, life-threatening  Systemic hypersensitivity reaction  Decreased blood pressure caused by release of histamine  Airway obstruction  Severe hypoxia  Can be caused by:  Latex materials  Insect stings  Nuts or shellfish; various drugs •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •30
  31. 31. Anaphylaxis (Cont.)  Signs and symptoms  Generalized itching or tingling, especially in oral cavity  Coughing  Difficulty breathing  Feeling of weakness  Dizziness or fainting  Sense of fear and panic  Edema around eyes, lips, tongue, hands, feet  Hives  Collapse with loss of consciousness •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •31
  32. 32. Effects of Anaphylaxis •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •32
  33. 33. Signs and Symptoms of Anaphylaxis •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •33
  34. 34. Treatment for Anaphylaxis  Requires first aid response:  Administer EpiPen if available  Call 911 (many paramedics can start drug treatment and oxygen)  Treatment in emergency department:  Epinephrine  Glucocorticoids  Antihistamines  Oxygen  Stabilize BP •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •34
  35. 35. Type II: Cytotoxic Hypersensitivity  Antigen is present on cell membrane  May be normal body component or exogenous  Circulating IgGs react with antigen  Destruction by phagocytosis or cytolytic enzymes •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •35  Example  Response to incompatible blood transfusion
  36. 36. Type II Hypersensitivity •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •36
  37. 37. Type III: Immune Complex Hypersensitivity  Antigen combines with antibody  Forms immune complexes, deposited in tissue  Activation of complement system  Process causes inflammation and tissue destruction  Examples:  Glomerulonephritis  Rheumatoid arthritis •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •37
  38. 38. Type III: Immune Complex Reaction •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •38
  39. 39. Type IV: Cell-Mediated or Delayed Hypersensitivity  Delayed response by sensitized T lymphocytes  Release of lymphokines  Inflammatory response  Destruction of the antigen  Examples:  Tuberculin test  Contact dermatitis  Allergic skin rash •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •39
  40. 40. Autoimmune Disorders  Development of antibodies against own cells or tissues  Autoantibodies are antibodies formed against self-antigens—loss of self-tolerance.  Disorder can affect single organs or tissues or can be generalized.  Examples:  Hashimoto thyroiditis, systemic lupus erythematosus, rheumatic fever, myasthenia gravis, scleroderma, pernicious anemia •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •40
  41. 41. The Autoimmune Process •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •41
  42. 42. Type IV: Cell-Mediated Delayed Hypersensitivity •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •42
  43. 43. Systemic Lupus Erythematosus (SLE)  Chronic inflammatory disease  Affects a number of organ systems  Characteristic facial rash—“butterfly rash”  Affects primarily young women  Incidence is higher in African Americans, Asians, Hispanics, Native Americans •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •43
  44. 44. Butterfly Rash Associated with SLE •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •44
  45. 45. SLE  Large number of circulating autoantibodies  Against DNA, platelets, erythrocytes  Formation of immune complexes  Deposited into tissues  Inflammation and necrosis  Vasculitis develops in many organs.  Impairs blood supply to the tissues •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •45
  46. 46. SLE (Cont.)  Sings and symptoms vary because of organ involvement but commonly include:  Arthralgia, fatigue, malaise  Cardiovascular problems  Polyuria  Diagnostic test  Serum antibodies, LE cells, other blood work  Treatment  Usually treated by a rheumatologist  Prednisone (glucocorticoid)  Nonsteroidal anti-inflammatory drugs •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •46
  47. 47. Common Manifestations of SLE •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •47
  48. 48. Immunodeficiency  Partial or total loss of one or more immune system components  Increased risk of infection and cancer  Primary deficiencies  Basic developmental failure somewhere in the system  Secondary or acquired immunodeficiencies  Loss of the immune response from specific causes  Can occur at any time during the life span • Infections, splenectomy, malnutrition, liver disease, immunosuppressant drugs, radiation, chemotherapy (cancer) •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •48
  49. 49. Immunodeficiency (Cont.)  Predisposition to the development of opportunistic infections  Caused by normal flora  Usually difficult to treat because of immunodeficiency  Prophylactic antimicrobial drugs may be used prior to invasive procedures. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •49
  50. 50. Acquired Immunodeficiency Syndrome (AIDS)  AIDS—chronic infectious disease caused by the human immunodeficiency virus (HIV)  HIV destroys helper T cells—CD4 lymphocytes  Loss of immune response  Increased susceptibility to secondary infections and cancer  Prolonged latent period  Development may be suppressed by antivirals •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •50
  51. 51. AIDS (Cont.)  HIV-positive individual  Virus is known to be in the body.  No evidence of immunosuppression •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •51  AIDS  Marked clinical symptoms, multiple complications  Individual often identified as HIV-positive before development of AIDS  Current therapies start if HIV infection is diagnosed in the early stages.
  52. 52. Stages in the Development of AIDS •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •52
  53. 53. History of AIDS  First case recognized in 1979; HIV identified in 1984  Evidence of earlier sporadic cases  Now considered to be a pandemic  Occurs in men and women  2006, CDC: 1 million cases in North America  2007, UN: 33 million cases globally; 22 million of those in sub-Saharan Africa •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •53

×