1. HOW DOES OUR BODY FIGHT OFF INFECTION??? Our Body’s Defenses

2. The First Line of Defense  Stops germs from getting into the bloodstream.  Traps, repels and destroys germs BEFORE they make you sick.

3. Five Barriers that Protect the Body  Skin – the body’s largest barrier  Mucous membranes – Found in ears, eyes, nose and throat  Saliva  Tears  Stomach acid

4. The Second Line of Defense  Immune System  A combination of body defenses made up of cells, tissues and organs that help fight infections.  White Blood Cells  Cells that work together to warn, track down and destroy germs.

5. 3 Types of White Blood Cells  Phagocytes  T-Cells  B-Cells

6. Phagocytes These white blood cells send a warning that a germ (invaders) has entered the bloodstream

7. T-Cells These white blood cells track down the invading germ and mark the germ with antibodies.

8. B-Cells These white blood cells destroy germs and anything else marked with an antibody. Sometimes the b-cells need back-up support in the form of medicine in order to fight the really tough germs.