1. Chapter 40 “The Immune System”
40.1 “Disease”
Objective:
Define the term “disease”
Describe “Germ Theory” & “Koch’s Postulates”
Discuss disease Transmission & Prevention.

2. Introduction (Do not write)
How would you define an infection?
Sickness, contamination of some sort.
By what?
Bacteria, or some “other” disease causing organism.
How does the human body become infected?
Cuts, breathing, eating

3. Disease
A disease is any change, other than injury, that disrupts “normal” body functions.
Some are inherited (hemophilia), some are caused by environment, others by bacteria, viruses, or fungi.

4. Pathogens Infect the body Cause disease Virus Bacteria
Malaria Parasite

5. The Germ Theory
Observations made by Louis Pasteur & Robert Koch concluded that diseases were caused by “germs”, rather than “evil spirits”.
Koch developed guidelines to identify microorganisms that caused diseases

6. Agents of Disease Ideal conditions for pathogen growth - your body!
Most are harmless
Bacteria release toxins which make you sick
Viruses (non-living) invade cells and eventually cause them to pop

7. Transmission Coughing, sneezing, physical contact.
Contaminated food & water.
Infected animals.
Vectors - animals that carry the disease causing organism (ticks, mosquitoes)

8. Fighting Pathogens Prevention Drugs
Antibiotic – attacks cell wall of bacteria
Do not work against viruses – no cell wall

9. 40.2 “The Body’s Defense System”
Objective:
Identify Non-Specific & Specific Defenses.
Define/describe the term Immunity.

10. Introduction (do not write)
With so many pathogens, why aren’t you sick all the time?
Your body has a protective system; a series of defenses that guard against disease.
Like walls that act as barriers & security guards trained to spot invaders.

11. Immune System Primary defense against pathogens Nonspecific defenses
Block out everything
Specific defenses
Attack a specific pathogen

12. Nonspecific Defenses
First line of defense = the skin, mucus, sweat, stomach acid
Skin is the most important nonspecific defense.

13. Inflammatory Response
Second line of non-specific defenses
Pathogens may enter body through a cut
Area swells, gets red
WBC released into injured area
Pathogens vs. WBC

14. Inflammatory Response
Skin
Wound
Bacteria enter the wound
WBCs move into the area and engulf the bacteria and cell debris
Capillary

15. Specific Defenses Powerful defense against a “specific” pathogen.
S. defenses produce immunity against pathogens.
Two types of immunity: Anti-body & Cell Mediated Immunities.

16. Antibody Immunity Molecules on surface of pathogens called antigens
Antigens trigger immune response
B cells (WBC) make proteins called antibodies which stick to antigens

17. Vaccines First vaccine was in late 1700s against small pox
Weakened pathogen is injected into body
Body mounts an immune response without getting sick
Immune system develops a memory of the pathogen = permanent immunity

18. Cell-Mediated Immunity
Powerful Immune System weapon = Killer T cell.
Kill infected body cells.
Can cause transplantation rejection.
Helper T cells & Suppressor T cells.

19. Immune Disorders
Two main types of disorders: Auto-Immune (overreaction) & Weakening of I.S. (AIDS).
Allergies: overreaction to antigen in environment.
Histamines are released = inflammatory response.
Asthma

20. Auto-Immune Diseases Immune System attacks body’s own cells.
Ex - Rheumatoid arthritis & Multiple sclerosis

21. HIV/AIDS HIV attacks T cells Kills T cells = kills immune system
New viruses leaving an
infected T cell

22. 40.3 “Cancer”
Objective:
Define Cancer.
Identify causes of Cancer.

23. Cancer 2nd leading cause of death in U.S
Cancer is uncontrollable cell growth which forms malignant tumors.
Caused by mutations, or changes in DNA.

24. Causes
Viruses
HPV is sexually transmitted and may lead to reproductive cancers.
Hepatitis leads to liver cancer.

25. Causes of Cancer... Radiation = UV light from the Sun.
Chemicals = carcinogen
Genetics
Treatment: surgeries, chemotherapy