1. Fighting Diseases:
The Immune System

2. How is Bacteria and other Diseases Spread?
Moisture droplets in air
Dust
Direct body to body contact (skin, fluids, etc)
Fecal contamination
Animal bites
Wounds

3. Why do we need an Immune System?
Many bacteria are pathogens  they are disease-causing organisms

4. Why do we need an Immune System?
An immune system defends our body against pathogens and build up an immune response for future incidents

5. Why do we need an Immune System?
Tonsil – filter out infectious organisms
Thymus – contain specialized WBCs
Liver – its WBCs removes organisms from blood

6. Why do we need an Immune System?
Spleen – removes weird cells from blood
Bone marrow – production of WBC
Lymph nodes – filters; produces antibodies

7. Immune System Response: 1st Line of Defense - Structural
Skin: keeps organisms and allergens from entering
Sweat : contains salts that are poisonous to bacteria

8. Immune System Response: 1st Line of Defense - Structural
Lysozyme: enzyme in tears, saliva, mucus, perspiration; digests bacterial cell walls
Cilia in respiratory passages: mucus helps trap bacteria
Stomach acid: low pH kills pathogens

9. Immune System Response: 2nd Line of Defense – Cellular
The Lymphatic System  network of organs, vessels and lymph nodes throughout body
Vessels transport fluid lymph (has lymphocytes, also known as white blood cells) from lymph nodes to rest of body

10. Immune System Response: 2nd Line of Defense – Cellular
When bacteria invades the body, WBC become activated as macrophages and seeks out the bacteria = engulf them and digest them using enzymes

11. Immune System Response: 3rd Line of Defense
Antibodies attack invaders  GOOD
Antigen is a foreign material that attacks the body  BAD.

13. Immune System Response: 3rd Line of Defense
Antibodies signal macrophages to destroy a particular antigen
Memory cells remember how to produce specific antibodies for future invasions.

14. Types Of Immunity: ACTIVE IMMUNITY
Lasting protection against an invader through the manufacture of antibodies (ie. previous infection, some vaccinations)

15. Types Of Immunity: PASSIVE IMMUNITY:
Temporary protection against a particular disease by the direct introduction of antibodies (ie. mom to baby, vaccinations)

16. Types Of Immunity: VACCINE:
Dead or weakened bacteria; body reacts to create to antibodies.