1. The Body’s Defense System
Chapter 31
The Body’s Defense System

2. The Germ Theory of Disease
Infectious disease is caused by pathogens that can spread the disease from one organism to another

3. Pathogen
Disease causing organism
Ex.) bacteria, fungi, virus, protists

4. Transmission of Infectious Diseases
Airborne
Physical contact
Contaminated food or H2O
Sexual contact
Animals (ex. Lyme disease)

5. The human body
has three lines
of defense
against infections

6. The First Line: Barriers
Physical & chemical (non-specific defenses)

7. Examples: Skin, Hair Mucous membranes Saliva Stomach acid & enzymes
Sweat, tears

8. The Second Line: Internal Nonspecific Defenses
3 types:
White blood cells
Inflammatory response
Specialized proteins

9. White Blood Cells
Travel through the body engulfing foreign invaders or destroying infected & abnormal acting cells

10. Macrophage

11. Macrophage and E. coli pink = macrophage
yellow = bacteria; note rod-like structure of bacillus

12. White Blood Cells
They are able to recognize “self” from “non-self” based on proteins on cell membranes

13. These cells are from the same person so they have the same “self” proteins on their cell membranes

14. Inflammatory Response
Body tries to isolate pathogen
Proteins are released that create blood flow and attract WBCs

15. Inflammatory Response
Causes redness, heat, swelling, pain at the location of injury

17. Inflammatory Response
If pathogen enters the blood the body spikes fever to try to destroy it…

18. Specialized Proteins (cytokines): released by cells to help destroy invaders
Histamine – increase blood flow, can cause watery eyes and runny nose
Interferon – prevents viral reproduction in infected cells
Interleukins – call WBC reinforcement and trigger fever

19. The Third Line: Targeted Defense
The immune response is a specific response to a “non-self” protein (antigen)

20. STARTING AN IMMUNE RESPONSE
Foreign invaders - viruses, bacteria, allergens, toxins and parasites - constantly bombard our body.
      
The response to this assault is a carefully orchestrated and controlled interaction between immune cells with the ultimate goal to eliminate the invader by pathogen-specific mechanisms.

21. Antigens cause a Specific Immune Response
A protein that is on the cell membrane and triggers an immune response

23. Macrophage ingesting yeast
During an oxidative burst, there is increased oxygen consumption, increased production of hydrogen peroxide and superoxide anion, and increased glucose oxidation. This results in the production of several microbicidal oxidizing agents in the lysosomes (which are the essentially the cell’s garbage disposal system), including superoxide anion, hydroxyl radical, singlet oxygen, and hydrogen peroxide. These will oxidize lipids, such as in the bacterial membranes causing lysis of the bacteria, and will oxidize or cross-link protein destroying their function. The primary enzyme involved in catalyzing the oxidation of foreign materials in the phagocytes is myeloperoxidase, which is contained in the lysosomes. Superoxide dismutase is also involved.

24. Macrophage
A large WBC that travels the body and engulfs foreign invaders (phagocytosis)
It displays the specific antigen and activates Helper T lymphocytes

26. Helper T Lymphocytes Recognize the antigen displaying WBC
Secretes chemicals that activate both cytotoxic T cells and B lymphocytes
Mature in Thymus gland

28. Defend primarily against bacteria & viruses by creating antibodies
Develop in Bone marrow
B Cell Lymphocytes

30. Antibodies Attach to Antigens
Antibodies - proteins found on the surface of WBCs or free in the plasma. Bind to SPECIFIC antigens to inactivate pathogens.

33. Cytotoxic T Cell Lymphocytes
develop with the ability to attack infected cells or kill the body’s abnormal cells (to prevent cancer)

36. Memory Cells
Both type B & T lymphocytes produce memory cells that will activate when exposed to the same pathogen

37. A Summary of the Immune Response – 3 min

38. The Third Line of Defense
The Immune Response
The Third Line of Defense

39. 1. Macrophage (WBC) takes in pathogen by phagocytosis
2. Pathogen completely engulfed
3. Pathogen is digested

40. WBC
PATHOGEN
ANTIGEN

41. 4. WBC “displays” the antigens; WBC releases chemicals to attract Helper T cells
5. Helper T cells (WBCs)
6. Helper T cells bind to antigens

42. WBC w/ ANTIGENS
Helper
T Cells
Bind To
Antigens
HELPER T
CELLS

43. 7. chemicals are secreted to begin a response
8. Helper T cells activate cytotoxic T (9) cells and memory T cells (10)

44. Chemical Secretion Memory T cells Helper T cells activate
TC & TM cells
Chemical
Secretion
TC cells destroy
pathogen
Memory
T cells

45. 14. Plasma B cells secrete… 15. Antibodies (destroy pathogen)
7. chemicals are secreted to begin a response
11. B cells are activated
12. B cells divide
13. Memory B cells are made
14. Plasma B cells secrete…
15. Antibodies (destroy pathogen)

46. B cells develop Chemical into plasma cells Secretion Plasma Memory
B cells are activated & divide
B cells
develop
into plasma cells
Plasma
Chemical
Secretion
Memory
B cells
which make antibodies

47. The Third Line of Defense
The Immune Response
The Third Line of Defense

48. Vaccines
stimulate the
immune response

49. 1796, used cowpox to provide immunity to small pox
Vaccine development
Edward Jenner
1796, used cowpox to provide immunity to small pox
The term vaccine comes from vaccinus, Latin for “from cow”. Jenner was an English doctor who noticed that milkmaids who were exposed to cowpox didn’t contract the more virulent disease of small pox. Jenner injected a milkmaid that had not contracted cowpox with that pathogen. The milkmaid developed immunity to smallpox.
Pasteur studied anthrax, a fatal disease of cattle, and developed a weakened or attenuated form of the bacteria that causes the disease. He inoculated 25 sheep with the vaccine and then inoculated this group and an additional 25 sheep with the anthrax bacillus several days later. The 25 sheep that had not been vaccinated died, while the vaccinated sheep were protected. He also worked on developing a vaccine for rabies and performed the first successful test on a young boy whose mother pleaded with Pasteur to treat her son after the boy had been bitten by a rabid dog. The boy underwent treatment with vaccinations for 10 days and recovered completely.
Polio is a disease of the central nervous system, specifically the spinal cord and is caused by a virus. Previously, the greatest incidence of the disease was in children between the ages of 5 and 10. There were over 57,000 cases of polio diagnosed in Because we have an effective polio vaccine, very few cases of the disease are diagnosed each year. The first vaccine was developed by Jonas Salk. The Sabin oral polio vaccine is the type most commonly administered in the U.S.
Koch’s Postulates are still used as the standard protocol today to prove that a pathogen causes a specific disease. A diagram of the process can be found on the next slide, entitled “Vaccine development uses Koch’s Postulates”.

50. 1885, developed vaccines for rabies & anthrax
Vaccine development
Louis Pasteur
1885, developed vaccines for rabies & anthrax
The term vaccine comes from vaccinus, Latin for “from cow”. Jenner was an English doctor who noticed that milkmaids who were exposed to cowpox didn’t contract the more virulent disease of small pox. Jenner injected a milkmaid that had not contracted cowpox with that pathogen. The milkmaid developed immunity to smallpox.
Pasteur studied anthrax, a fatal disease of cattle, and developed a weakened or attenuated form of the bacteria that causes the disease. He inoculated 25 sheep with the vaccine and then inoculated this group and an additional 25 sheep with the anthrax bacillus several days later. The 25 sheep that had not been vaccinated died, while the vaccinated sheep were protected. He also worked on developing a vaccine for rabies and performed the first successful test on a young boy whose mother pleaded with Pasteur to treat her son after the boy had been bitten by a rabid dog. The boy underwent treatment with vaccinations for 10 days and recovered completely.
Polio is a disease of the central nervous system, specifically the spinal cord and is caused by a virus. Previously, the greatest incidence of the disease was in children between the ages of 5 and 10. There were over 57,000 cases of polio diagnosed in Because we have an effective polio vaccine, very few cases of the disease are diagnosed each year. The first vaccine was developed by Jonas Salk. The Sabin oral polio vaccine is the type most commonly administered in the U.S.
Koch’s Postulates are still used as the standard protocol today to prove that a pathogen causes a specific disease. A diagram of the process can be found on the next slide, entitled “Vaccine development uses Koch’s Postulates”.

51. Jonas Salk/Albert Sabin
Vaccine development
Jonas Salk/Albert Sabin
1955, Salk developed injectable vaccine for polio
1961, Sabin developed an oral vaccine
The term vaccine comes from vaccinus, Latin for “from cow”. Jenner was an English doctor who noticed that milkmaids who were exposed to cowpox didn’t contract the more virulent disease of small pox. Jenner injected a milkmaid that had not contracted cowpox with that pathogen. The milkmaid developed immunity to smallpox.
Pasteur studied anthrax, a fatal disease of cattle, and developed a weakened or attenuated form of the bacteria that causes the disease. He inoculated 25 sheep with the vaccine and then inoculated this group and an additional 25 sheep with the anthrax bacillus several days later. The 25 sheep that had not been vaccinated died, while the vaccinated sheep were protected. He also worked on developing a vaccine for rabies and performed the first successful test on a young boy whose mother pleaded with Pasteur to treat her son after the boy had been bitten by a rabid dog. The boy underwent treatment with vaccinations for 10 days and recovered completely.
Polio is a disease of the central nervous system, specifically the spinal cord and is caused by a virus. Previously, the greatest incidence of the disease was in children between the ages of 5 and 10. There were over 57,000 cases of polio diagnosed in Because we have an effective polio vaccine, very few cases of the disease are diagnosed each year. The first vaccine was developed by Jonas Salk. The Sabin oral polio vaccine is the type most commonly administered in the U.S.
Koch’s Postulates are still used as the standard protocol today to prove that a pathogen causes a specific disease. A diagram of the process can be found on the next slide, entitled “Vaccine development uses Koch’s Postulates”.

52. Vaccines
Dose of a pathogen or part of a pathogen that is disabled or destroyed  no longer harmful

53. Vaccines Different types: Use just antigens of pathogen
Grind or heat pathogen so it can’t function
Similar version of pathogen
Booster shots

54. Stages in
Vaccine-Induced
Immunity

55. Active Immunity
When your body produces antibodies against an infection
Memory Cells are Made

56. Active Immunity
2 examples:
Previous infection
Vaccines

57. Passive Immunity
When you receive antibodies from another source

58. Passive Immunity Examples: Fetus from mother
Traveling  antibodies temporarily protect

59. Disorders of the immune system are major health problems
Use textbook to fill in
page 6 in your notes

60. ABO Blood Groups
Blood typing is determined by the antigens present on the surface of the RBCs.
There are A & B antigens

61. This results in Four possible blood types:
Blood Groups
This results in Four possible blood types:
A, B, AB, O

62. BLOOD TYPE A

63. BLOOD TYPE B

64. BLOOD TYPE AB

65. BLOOD TYPE O

67. A B AB O BLOOD TYPE A B A & B neither A nor B Blood Type
RBC Antigens Present
Blood Type A B
A & B
neither A nor B A B AB O

68. Antibodies Present in Plasma
BLOOD TYPE
Blood Type
Antibodies Present in Plasma A B AB O B A
None
A & B

69. How Many Blood Types?
Type AB
Type A
Type B
Type O

70. A O B O A B AB O O A B AB O BLOOD TYPE Blood Type Universal Recipient
Can Receive Type: A B AB O A O B O A B AB O O
Universal Recipient

71. A AB B AB AB A B AB O A B AB O BLOOD TYPE Blood Type Universal Donor
Can Donate To: A B AB O A AB B AB
Universal
Donor AB A B AB O

72. Organ Transplants
Possible rejection because body is recognizing “self” versus “non-self” tissues

73. Organ Transplants
Medications suppress immune system to decrease rejection  but lowers defense system against other infections

74. Plasma Donations
In an emergency situation plasma may be transfused instead of blood cells. Why??
No typing is necessary!

75. Blood Typing Game
Turn to Page 8

76. Add the Rh Factor… A- A+

77. Determining Blood Type:

78. A B Rh When we add a patients blood to each test tube:
If test tube A clumps,
the blood contains the _______ antigen.
If test tube B clumps,
If test tube Rh clumps, A B Rh

79. Blood Typing Game