1. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Memmler’s The Human Body in Health and Disease 11 th edition Chapter 17 Body Defenses, Immunity, and Vaccines

2. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Immune System Types of general body defenses against disease Nonspecific defenses –Effective against any harmful agent Specific defenses –Effective against a certain agent only

3. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Why Do Infections Occur? Factors involved in infection Portal of entry Virulence of organism –Aggressiveness –Toxin production Dose (number) of pathogens Individual condition (predisposition) to infection

4. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-1: What are some factors that influence the occurrence of infection?

5. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonspecific Defenses Successive lines of defense Simple outer barriers More complicated responses Immunity (ultimate defense mechanism)

6. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Chemical and Mechanical Barriers Skin Mucous membranes –Cilia Body secretions –Tears –Perspiration –Saliva –Digestive juices Reflexes –Sneezing –Coughing –Vomiting –Diarrhea

7. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-2: What tissues constitute the first line of defense against the invasion of pathogens?

8. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Phagocytosis White blood cells take in and destroy waste and foreign material Neutrophils Macrophages

9. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Natural Killer Cells Type of lymphocyte Can recognize body cells with abnormal membranes Found in lymph nodes, spleen, bone marrow, blood Secrete protein that breaks down cell membrane

10. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: Which of the below are NOT one of the two main leukocytes involved in phagocytosis? a. neutrophils b. basophils c. macrophages

11. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: b. basophils

12. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Inflammation Infection is inflammation caused by pathogens Inflammatory reaction –Heat, redness, swelling, pain –Cells release histamine –Leukocytes enter tissue Granulocytes, macrophages, mast cells –Leukocytes and plasma produce inflammatory exudate –Pus is produced –Lymph nodes enlarge

13. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Fever As phagocytes work, they release substances that raise body temperature Stimulates phagocytes Increases metabolism Decreases some organisms’ ability to multiply

14. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Interferon Group of substances that prevent nearby cells from producing more virus –IFN a (alpha) –IFN b (beta) –IFN g (gamma) Also acts nonspecifically on immune system cells

15. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-3: What are some nonspecific factors that help to control infection?

16. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins ImmunityImmunity Power to overcome a specific disease agent Innate immunity –Inherited in genes Adaptive immunity –Develops after birth –Acquired naturally or artificially –Active or passive

17. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Types of immunity

18. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Innate Immunity Differences in physical constitution Species immunity Individual immunity

19. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Adaptive Immunity Develops in a person During lifetime From encounters with specific harmful agents

20. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-4: What is the difference between innate and adaptive immunity?

21. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: The fact that people don’t get many diseases from animals is a result of what type of immunity? a. artificial adaptive immunity b. individual immunity c. species immunity

22. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: c. species immunity

23. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Antigens Foreign substances that Enter body Induce immune response of certain lymphocytes –T cells –B cells

24. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins T Cells Originate in stem cells in bone marrow Change to T cells in thymus Become sensitized to specific antigens Produce cell-mediated immunity –Cytoxic T cells –Helper T cells –Regulatory T cells –Memory T cells Macrophages

25. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Activation of a helper T cell by a macrophage (antigen- presenting cell). Zooming In: What is contained in the lysosome that joins the phagocytic vesicle?

26. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-5: What is an antigen? Checkpoint 17-6: List four types of T cells.

27. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins B Cells and Antibodies Antibody (Ab) also known as immunoglobulin (Ig) is substance produced in response to antigen Manufactured by B cells (B lymphocytes) Must mature in fetal liver or in lymphoid tissue Provides humoral immunity Contained in gamma globulin fraction of blood plasma

28. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: Which type of T cells release interleukin? a. cytotoxic T cells b. regulatory T cells c. helper T cells

29. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: c. helper T cells

30. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Activation of B cells. The B cell combines with a specific antigen. The cell divides to form plasma cells, which produce antibodies. Some of the cells develop into memory cells, which protect against reinfection. Zooming In: What two types of cells develop from activated B cells?

31. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-7: What is an antibody? Checkpoint 17-8: What type of cells produce antibodies?

32. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Antigen–Antibody Reaction Complement is the enzymatic activity of a group of nonspecific proteins in blood that: Coats foreign cells Destroys cells Promotes inflammation Attracts phagocytes

33. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-9: What is complement?

34. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Naturally Adaptive Immunity Immunity acquired through contact with a specific disease organism Active immunity Passive immunity

35. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-10: What is the difference between the active and passive forms of naturally acquired immunity?

36. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Artificially Adaptive Immunity Vaccination (immunization) can cause a person’s immune system to manufacture antibodies Preventive measure Risk of side effects

37. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Types of Vaccines Live Attenuated Toxoid Killed by heat or chemicals Antigenic component Genetically engineered

38. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Boosters Active immunity does not always last a lifetime Repeated inoculations (booster shots) help maintain high titer of antibodies in the blood Number and timing varies with vaccines

39. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Examples of Vaccines Whooping cough (pertussis) Diphtheria, tetanus toxoid (Td) Haemophilus influenzae type B (Hib) Pneumococcal vaccine (PCV) Viral –Inactivated polio, oral polio –Measles (rubeola), mumps, rubella (MMR) –Hepatitis B –Hepatitis A –Chicken pox (varicella); vaccine for shingles now available for those >60 yr –Influenza –Rabies –Rotavirus –HPV (human papillomavirus) for girls 11-26

40. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-11: What are some bacterial diseases for which there are vaccines? Checkpoint 17-12: What are some viral diseases for which there are vaccines?

41. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: For which of these diseases is the vaccine administered after (not before) exposure to the pathogen? a. pertussis b. rabies c. HPV

42. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: b. rabies

43. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Passive Immunity Acquired by administration of immune serum (antiserum) Short-lived immunity Used in emergencies Often derived from animals May cause sensitivity reaction

44. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-13: What is an immune serum and when are immune sera used?

45. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Disorders of the Immune System Resulting from overactivity –Allergy –Autoimmune disease Resulting from underactivity –Hereditary –Infections –Environmental

46. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Allergy Abnormal reactivity to one’s own tissues Factors –Disease –Loss of immune system control –Cross-reaction of antibodies and self antigens Treatments –Immune-suppressing drugs –Chemotherapy/stem cell replacement

47. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Immune Deficiency Diseases Failure of immune system May involve any part of system Varies in severity Congenital or acquired (e.g., AIDS) HIV –A retrovirus; uses reverse transcriptase enzyme

48. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Multiple Myeloma Cancer of blood-forming bone marrow cells Effects of disease –Lowered resistance to infection –Anemia –Bone pain –Bone tissue loss –Kidney failure Treatment –Chemotherapy –Bone marrow transplants

49. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-14: What are some disorders of the immune system?

50. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Immune System and Cancer Immune surveillance –Declines with age Immunotherapy –T cells activated with interleukin –Vaccines

51. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Transplantation and Rejection Syndrome Caused by normal antigen–antibody reaction Reduced by –Tissue typing –Immune suppression drugs

52. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 17-15: What is the greatest obstacle to tissue transplantation from one individual to another?

53. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins End of Presentation