1. Immune System

2. Standards: 4d. Examine various conditions that change normal body functions (e.g. tissue rejection, allergies, injury, diseases and disorders) and how the body responds.

3. Pathogens are disease causing organisms examples: bacteria, viruses, fungi and protists

4. The body has 3 main lines of defense to prevent invading microbes from getting the upper hand First line of defense Made up of the skin and mucous membranes skin covers the outside of the body

5. mucous membranes line the body’s internal surfaces (digestive tract, nasal passages, respiratory passages, and reproductive tract) Together, the skin and mucous membranes function to prevent microbes from entering the body

6. when pathogens penetrate the 1 st line of defense (through cuts or wounds), the 2 nd line of defense comes into play

7. Second line of defense Made up of: 1. Three types of cells that kill invading microbes a. Macrophages are WBCs that travel through the body to kill invading bacteria by ingesting them

8. b. Neutrophils are WBCs that release chemicals that kill invading bacteria and themselves in the process

9. c. Natural killer cells are defense cells that kill any body cell that has become infected with a virus more importantly, natural killer cells are our best defense against cancer

10. they detect and kill cancer cells before they can form tumors

11. 2. Complement – is a group of proteins that circulate in your bloodstream they function to kill invading bacteria and fungi

13. 3. The inflammatory response is to series of events that functions to suppress infection and speed healing it occurs anytime you have been injured

14. A series of events occur during an inflammatory response 1. Damage cells release alarm chemical that 2. Attract neutrophils and macrophages to the damaged area which

15. 3. Cause local blood vessels to dilate increasing blood supply to the damaged area This is what causes the four classical symptoms of inflammation (heat, redness, pain, and swelling)

17. The cardinal signs of inflammation are rubor (redness), calor (heat), tumor (swelling), dolor (pain), and loss of function.

18. Video Clips from http://www.goldiesroom.org/video_archive.htm http://www.goldiesroom.org/video_archive.htm about HIV and the Immune System: Immune System 1 Inflammation (2 min)

19. 4. Temperature response – activated macrophages (those consuming invading bacteria) send signals to the brain to increase your body temperature above normal (98.6  F / 37  C)

20. Low grade temperatures (less than 103  F/ 39  C) speed the healing process because they inhibit the growth of bacteria However, high grade temperatures (greater than 105  F/ 41  C) are often fatal because they destroy important enzymes in the body

21. Third line of defense Made up of your immune system It functions to combat major invasions, and comes into play only when your first 2 lines of defense have failed to kill the invading pathogens

22. 1. Key players in the immune system a. Macrophages – WBCs that initiate the immune response they release an alarm signal that functions to activate Helper T cells

23. b. Helper T cells – WBCs that function to activate Killer T cells and B cells c. Killer T cells – WBCs that recognize and kill body cells infected with a virus

24. d. B cells – WBCs that produce antibodies that mark pathogens for destruction by macrophages and natural killer cells some of these activated B cells will become memory cells that remain in your body for a long time – sometimes for life

25. These memory B cells are programmed to recognize the same pathogen that they encountered earlier in your life If they ever encounter that same pathogen again, they rapidly produce large amounts of antibodies that destroy the pathogen before they have a chance to cause the disease a second time

26. Video Clips from http://www.goldiesroom.org/video_archive.htm http://www.goldiesroom.org/video_archive.htm about HIV and the Immune System: Antibodies Silly Bill Nye (2 min) Immune System 2 Humoral Immunity (1 min) Immune System 3 Cell Mediated Immunity (3 min)

27. Viruses: Understanding Viruses (50 min) An Inside look at the Flu (25 min)

28. 2. Vaccination – prevent disease by tricking your immune system into thinking your body has been invaded by a particular pathogen

29. The vaccine you receive usually contains a dead or disabled pathogen which cannot cause disease, but does result in the formation of memory B cells that patrol the body preventing future infections by the same pathogen

30. Vaccinations exists for many diseases: polio, tetanus, diphtheria, measles, and smallpox

31. Video Clips from http://www.goldiesroom.org/video_archive.htm http://www.goldiesroom.org/video_archive.htm about HIV and the Immune System: Vaccination Discovery (3 min)

32. Polio

33. Tetnus

34. Diphtheria

36. Measles

38. Smallpox

41. Smallpox vs. Chickenpox

42. smallpox vaccinations are no longer required because this disease has been eradicated from the earth

43. http://www.historyofvaccines.org/co ntent/how-vaccines-work How vaccines work at the cellular level (Comp Book-Back of page 54)

44. Malfunctions and Failures of the Immune System 1. Autoimmune diseases – diseases in which the body attacks its own cells we do not know what triggers the development of these diseases

45. There are several different types of autoimmune diseases: a. Multiple sclerosis occurs when the immune system attacks and slowly destroys the myelin sheath that surrounds and protects your nerves

46. As the myelin is destroyed, your nerves lose their ability to conduct impulses This results in progressively worsening paralysis and eventually death there is no cure

47. b. Systemic lupus erythematosus – occurs when the immune system attacks and destroys your connective tissue, joints, and kidneys Eventually causes death there is no cure

48. c. Type 1 diabetes – occurs when the immune system destroys insulin-producing cells in the pancreas there is no cure, but can be controlled by taking daily insulin injections

49. d. Rheumatoid arthritis – occurs when the immune system attacks and destroys cartilage in your joints

50. As the cartilage is destroyed, bone begins rubbing against bone causing tremendous pain there is no cure

51. 2. Allergies – occur when the immune system mounts a major attack against a normally harmless substance For example, if you are allergic to pollen, your immune system treats the pollen as if it were a pathogen, causing nasal congestion and a runny nose

52. 3. SCID (severe combined immunodeficiency) – a rare disease in which a person is born with missing or inactive B cells and T cells This person has no immune system. Thus, they could be killed by a cold virus

53. The most famous patient with SCID was David, the “bubble boy”, who lived in a sterile plastic bubble for almost all of his life; he died in 1984 at the age of 12

54. 4. AIDS (acquired immune deficiency syndrome) – disease caused by HIV (human immunodeficiency virus) Although AIDS was first recognized as a disease in 1981, it has been around since 1959

55. HIV is transmitted by: 1. Sexual intercourse with an infected person 2. Sharing hypodermic needles with an infected person (IV drug use)

56. 3. Receiving blood transfusions or blood products (factor VIII used by hemophiliacs) from an infected individual HIV is not transmitted through air, on toilet seats, by shaking hands or sharing food or drink

57. There is no cure. HIV transmission can be prevented by not sharing hypodermic needles and abstinence. Condoms can help prevent HIV transmission, but there is no guarantee

58. In 1989, it was discovered from tissue samples that a British sailor died of AIDS in 1959 HIV causes death by attacking helper T cells. As a result killer T cells and B cells cannot be activated. Thus, the body is susceptible to infections and cancer

59. HIV infected individuals are considered to have AIDS when their helper T cell count falls below 200/mL (normal is 800 – 1000/mL)

60. Diseases that commonly cause death in AIDS patients are: Pneumocystis pneumonia Kaposi’s sarcoma (cancer of skin and mucous membranes)

61. Bill Nye Video Clips from http://www.goldiesroom.org/video_archive.htm http://www.goldiesroom.org/video_archive.htm about HIV and the Immune System: HIV (2-3 min) HIV and AIDS (1 min)

62. http://www.hhmi.org/biointeractive/disease/video.html Many video clips available from HHMI http://www.hhmi.org/biointeractive/disease/video.html Many animations available from HHMI Click here to link to a video clip about the HIV Life Cycle Or to access the video clip online, click hereclick here