1. Protecting your body from all invaders every second of every day
THE IMMUNE SYSTEM
Protecting your body from all invaders every second of every day
Immune System: Body’s primary defense against disease-causing microorganisms.

2. WRITE EVERYTHING YOU KNOW ABOUT THE IMMUNE SYSTEM

5. ON THE DEFENSE
Pathogens: These enemies are foreign bodies that enter your body and can cause disease.
They could be viruses or bacteria

6. Prokaryotic microorganisms Present in most habitats on earth
Bacteria
Prokaryotic microorganisms
Present in most habitats on earth
Virus
Infectious agent that replicates inside the living cells of an organism

7. HOW DO YOU COME IN CONTACT WITH PATHOGENS EVERY DAY?
THINK PAIR SHARE
HOW DO YOU COME IN CONTACT WITH PATHOGENS EVERY DAY?

8. HOW COULD YOU LIVE IF YOU HAD NO IMMUNE SYSTEM?

10. FIRST LINE OF DEFENCE
The first line of defense blocks a large percent of the pathogens that want to invade our bodies.
Our skin: The dead outer layer of the skin, known as the epidermis, provides a physical barrier. It acts much like the wall protecting a castle from invaders.

11. FIRST LINE OF DEFENCE The sweat and oil on our skin
These provide a slightly acidic environment and prevents some pathogens from growing on our body and skin.

12. FIRST LINE OF DEFENCE Gastric juices in our stomach
Also provide a slightly acidic environment.
This helps to kill some pathogens that we eat.

13. FIRST LINE OF DEFENCE Mucus in our nose and respiratory system.
As you breathe in, foreign particles and bacteria bump into mucus throughout your respiratory system and become stuck

14. SECOND LINE OF DEFENCE
While the first lines of defense work to keep out a majority of invaders, some sneaky ninja pathogens make it through undetected.
This is called an immune response and the job of the super-heroes is to destroy the pathogens.

15. SECOND LINE OF DEFENCE There are two types of immune responses:
Innate immune response
Acquired immune response

16. INNATE IMMUNE RESPONSE
General and non-specific
Very fast acting
Its first action is inflammation
Swelling, fever, and redness in one area
Phagocytes are released (first superhero)
White blood cells patrol the body searching for pathogens and EAT them
phagocyte breaks the foreign particles apart in organelles called lysosomes

17. AQUIRED IMMUNE SYSTEM
Highly specific attack on a particular pathogen or antigen.
Antigen: Any nonliving substance the body cannot recognize (anything from virus to a sliver)
Can take a week to develop
Gives you active immunity
Your body remembers the specific antigen and develops antibodies against the antigen

18. AQUIRED IMMUNE SYSTEM B cells
Warning System: Recognize antigens in the body
Produce antibodies to fight antigens
Antibodies:
cover antigen
Prevent antigen from infecting body cells
Mark it for destruction by white blood cells

19. AQUIRED IMMUNE SYSTEM Killer T cells Work alone and destroy antigens
Helper T cells
Roam the body searching for invaders
When invaders are found, T cells signal B cells to start immune response

20. Cell before infection…
Viruses
Viruses enter body cells, hijack their organelles, and turn the cell into a virus making-factory. The cell will eventually burst, releasing thousands of viruses to infect new cells.
…and after.
Cell before infection…

21. What happens to already infected cells?
Interferons
Virus-infected body cells release interferon when an invasion occurs
Interferon – chemical that interferes with the ability to viruses to attack other body cells
What happens to already infected cells?

22. Vaccines Polio 1952 60,000 cases in the US 3000 fatalities
1955 Salk vaccine
1979 eliminated in US
Polio – virtually eradicated from western hemisphere. Horrible from in US from when the Salk vaccine was widely made available
The height of the epidemic was ,000 cases 3000 fatalities 5% fatality rate. Typically transmitted in poop (not washing hands or drinking contaminated water)

23. How do vaccines work?
Vaccines are made up of weakened viral particles.
The weakened particles stimulate a Primary Immune Response – body recognizes agent as foreign, destroys it and remembers it, so next time it can recognize and destroy the virus right away
When the pathogen actually attacks, the Secondary
Immune Response occurs.
memory cells divide and produce large numbers of antibodies, are produced stopping the infection before you can become sick 23