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 body’s ability to destroy pathogens before they cause the disease
Two types:
Active
Passive

11. Active Immunity
your own body produces antibodies in response to the presence of a pathogen
1.When you get sick- T & B cells fight off the pathogen, they remember it (chicken pox)
2.Vaccination- some of the disease is injected into you

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