| A | B |
|---|
| first line defense | prevents pathogens from entering the body |
| skin | protective barrier from pathogens |
| respiratory system | traps pathogens with mucus and cilia and removes with sneezes and coughs |
| digestive system | produces saliva, enzymes, and hydrochloric acid that kill bacteria |
| circulatory system | produces white blood cells that digest foreign organisms |
| inflammation | redness and swelling caused by excess blood flow fighting off pathogens |
| antigen | molecules that are foreign to the body |
| antibody | protein made in response to specific antigens |
| active immunity | body makes own antibodies to fight off antigens |
| passive immunity | body receives antibodies from another source to fight off antigens |
| vaccine | form of antigen that causes the body to produce antibodies |
