| A | B |
| epidermis | the outer layer of the skin |
| melanin | a pigment that gives skin its color |
| dermis | the inner layer of skin |
| pore | an opening through sweat reaches the surface of the skin |
| follicle | structure in the dermis of the skin from which a strand of hair grows |
| pathogen | an organism that causes disease |
| infectious disease | a disease caused by the presence of a living thing in the body |
| toxin | a poison produced by bacterial pathogens that damages cells |
| immune response | part of the body's defense against pathogens, in which cells of the immune system react to each kind of pathogen with a defense targeted specifically at that pathogen |
| antibody | a protein produced by a B cell of the immune system that destroys pathogens |
| white blood cells | a blood cell that fights disease |
| inflamatory response | part of the body's defense against pathogens, in which fluid and white blood cells leak from blood vessels into tissues, and white blood cells destroy pathogens |
| T-cells | a lymphocyte that identifies pathogens and distinguishes one pathogen from another |
| antigen | a molecule that the immune system recognizes either as part of the body or as coming from outside the body |
| integumentary system | a collection of organs that helps the body maintain a stable and healthy internal environment, organs include skin, hair, and nails |
| phagocyte | a white blood cell that destroys pathogens by engulfing them and breaking them down |