1. 3.1 – Immune System Recap

2. What is a… Pathogen  Disease causing invaders of our bodies
(ie. bacteria, viruses, fungi, parasites)
Antigen
 Non-living foreign substance that triggers an immune response

3. How are Infectious Diseases Spread?
Direct Contact ~ Ex. Shaking hands.
Indirect Contact ~ Ex. Near a sneezer.
Water and Food ~ Ex. Drinking water.
Animal Bites ~ Ex. Rabies

4. First Line of Defense Skin Sweat & oil on skin Gastric juice
Mucus & cilia

5. What happens when you get a cut and some bacteria enters the wound?

6. Second Line of Defense 2 Responses: Innate (many animals have this)
Acquired (vertebrates have this)

7. Innate Immune Response
Quick & general (same) for all invaders
Inflammation (redness, swelling)
(flow of fluid & cells to the site)
Numbers of white blood cells called Phagocytes increase – they swallow invaders

9. Staph infection – abscess drainage
Abscess forms from buildup of pus at site of inflammation during infection (contains dead white blood cells)

10. Acquired Immune Response
Slow (but can eventually heal)
Attacks specific invader (pathogen, antigen, allergen)

11. Acquired Immune Response
Helper T Cell
 recognizes foreign invader & activates B Cells
B Cell  produces specific antibodies that match an antigen
(destroys, mark for destruction, prevent from infecting more cells)

12. Acquired Immune Response
Killer T Cell  destroys invaders
(even cancer cells)
Memory B Cell  stores antibodies to be reactivated quickly (active immunity)
(ex. chicken pox)

13. Comparison
Innate Acquired/Adapted
Fast Slow
General Specific

14. Video

15. If we are surrounded by pathogens, how is this possible?!?!

16. Important Discoveries in History
Joseph Lister
British surgeon in 1850’s
Noticed high death rates in surgeries
Hypothesized due to invisible germs
Experimental test  sterilized equipment and hands!
Reduced death rate

17. Mary Montagu – 1700’s Smallpox was a deadly disease in Europe
observed women in Turkey putting mild small pox pus onto children
children would develop blisters but healed quickly and did not get serious form of the disease
experimented on English prisoners
led to eradication of smallpox from England

18. Edward Jenner
observed people milking cows seemed immune to smallpox
they got cowpox (milder disease)
gave 8 year old boy cowpox by putting him near infected cows
 then tried to infect him with smallpox
Can these experiments be tested today?

19. Dark history of the Hudson Bay blankets
Controversy believed by many Canadian aboriginals is that British administrators supported the handing out of HBC point blankets contaminated with smallpox to wipe out population at Fort Pitt in late 1700s
 biological weapon
Hudson Bay Company claims soldiers sold used blankets without knowing
Regardless, these events contributed to the spread of this epidemic