| A | B |
|---|
| lysozyme | an enzyme that digests the cell walls of many bacteria and destroys microbes. |
| skin | barrier that cannot be penetrated by bacteria or viruses, counter pathogens with chemical defenses such as oil and sweat |
| mucus | viscous fluid secreted by cells that traps particles and expells them. |
| phagocytosis | ingestion of invading particles by certain types of white blood cells |
| macrophages | largest phagocytic cells, especially effective and long-living |
| inflammatory response | triggered by damage to tissue; blood vessels in the area of injury dilate, increasing blood supply, causing redness and heat, initiated by chemical signals |
| antigen | foreign substance that elicits an immune response; four functions: neutralization, agglutination of particulate antigens, precipitation of soluble antigens, and activation of complement |
| antibodies | speicalized lymphocytes produce these specific proteins that counteract antigensins to |
| active immunity | immunity conferred by recovering from an infectious disease; depends on the response of a person's own immune system |
| passive immunity | immunity gained by transferring antibodies from one individual to another |
| B cells | lymphocytes that carry out the humoral immune response |
| T cells | lymphocytes that function mainly in the cell-mediated immune response |
| humoral immunity | an immune response to antigens resulting in the production of antibodies that circulate as soluble proteins in blood plasma and lymph |
| cell-mediated immunity | immune response that depends on the direct action of cells |
| memory cells | cells that aid the immune system in recognizing an antigen previously encountered by the body |
| allergy | hypersensitivity of the body's defense system to certain enviromental allergens |
