1. How do we fight disease?
Immune System

2. Microorganisms that make us sick are called pathogens
Diseases caused by pathogens are called infectious diseases

3. Types of pathogens Bacteria Viruses: Fungi: Protists:
example: strep, tetanus
Viruses:
colds, flu
Fungi:
athlete’s foot & ringworm
Protists:
amoebic dysentery

4. How are pathogens spread?
A. Contact with an infected person
1. Direct contact: kissing, shaking hands
2. Indirect contact: sneezes
B. Contaminated food, water & soil
C. Contaminated objects
D. Infected animals

6. Body Defenses Barriers (First Line of Defense) 1. Skin
2. Breathing passages
Mucus
Cilia
3. Mouth & stomach
Saliva
Stomach acid

7. If something gets through the barriers:
Invaders cause damage to cells which trigger an inflammatory response (Second Line of Defense)
Fluid & white blood cells leak into tissues to fight the pathogens
Phagocyte- engulfs pathogens and digests them
Fever- higher temperature kills pathogens

8. Immune System (3rd Line of Defense)
If pathogen is bad enough for a fever, then the 3rd line of defense is triggered, the immune response
Immune system has cells to target specific pathogens

9. Immune System Cells T-Cells- identify the pathogens
B-Cells- produce antibodies in response to the antigens on the pathogen to fight each different type of pathogen
Go to p. 571 sketch the diagram in your book explaining how the T cells and the B cells fight off infection. (yes, I want you to copy the exact diagram and labels)

10. Preventing Infection
Immunity: the bodies ability to destroy pathogens before the cause the disease
Two types:
Active
Passive

11. Active Immunity
your own body produces antibodies in response to the presence of a pathogen
When you get sick and the T & B cells fight off the pathogen, the remember it, if it comes back they are ready (chicken pox) OR
Vaccination- when you are vaccinated some of the disease is injected into you to trigger an immune response

12. Passive immunity
When antibodies to fight disease come from some place other than your own body
Example: babies get antibodies through breast milk & from mothers blood before birth