| A | B |
| Disease | Any change, other than injury, that disrupts the normal function of the body for a extended period of time |
| Infection | When a potential disease causing organism enters your body. |
| Pathogens | Agents that can cause an infectious disease |
| Antigen | protein on the surface of a cell or virus |
| Antibody | Protein made to attack antigens |
| Skin | First line of defense |
| Macrophages | 2nd line of defense; nonspecific cells |
| Helper T cells | Direct the activities of the other immune system cells |
| Plasma B cells | Makes the antibody |
| Primary immune response | Body's reaction to a first encounter with an antigen |
| Secondary immune response | 2nd ecnounter with the same antigen |
| Inflammatory response | Nonspecific response to injury or infection |
| Killer T cells | Destroy the infected cells |
| Suppressor T cells | Deactivates the Killer T cells |
| Memory B cells | Remembers how to make an antibody |
| Memory T cells | Remembers how to be a killer T cell for that antigen |