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Vocab Ch 12 pt 2
Body Defenses
Term | Definition |
---|---|
Immune system | the body’s defenders against tiny but mighty enemies-- innate and the adaptive dense systems. |
innate defense system | responds immediately to protect the body from all foreign substances, whatever they are. also known as non-specific defense system |
adaptive defense system | mounts the attack against particular foreign substances. |
Immunity | the ability of the body to resist many agents (both living and nonliving) that can cause disease; resistance to disease. |
pathogens | disease-causing microorganism (e.g., some bacteria, fungi, viruses, etc |
lysozyme | an enzyme found in sweat, saliva, and tears that is capable of destroying certain kinds of bacteria |
Natural killer cells | roam the body in blood and lymph. A unique group of aggressive lymphocytes that can lyse and kill cancer cells, virus-infected body cells, and some other non-specific targets well before the adaptive arm of the immune system is enlisted in the fight. |
inflammatory response | a physiological response of the body to tissue injury; includes dilation of blood vessels and increased blood vessel permeability. |
histamine | a substance that causes vasodilation and increased vascular permeability |
kinins | group of polypeptides that dilate arterioles, increase vascular permeability, and induce pain. |
diapedesis | the passage of blood cells through intact vessel walls into the tissues |
Pus | the fluid product of inflammation composed of white blood cells, the debris of dead cells, and a thin fluid |
phagocytes | cell capable of engulfing and digesting particles or cells harmful to the body |
antimicrobial proteins | enhance the innate defenses either by attacking microorganisms directly or by hindering their ability to reproduce. |
complement | a group of plasma proteins that normally circulate in inactive forms; when activated by complement fixation, causes lysis of foreign cells and enhances phagocytosis and inflammation. |
complement fixation | occurs when complement proteins bind to certain sugars or proteins on the foreign cell’s surface |
membrane attack complexes (MAC) | produce lesions, complete with holes, in the foreign cell’s surface as a result of complement fixations. |
interferons | small proteins secreted to help defend cells that have not yet been infected |
fever | abnormally high body temperature |
pyrogens | an agent or chemical substance that induces fever |
immune response | antigen-specific defenses mounted by activated lymphocytes |
Humoral immunity | immunity provided by antibodies released by sensitized B cells and their plasma cell progeny. Also called antibody-mediated immunity |
cellular immunity | immunity conferred by lymphocytes called T cells; also called cell-mediated immunity |
antigen | any substance capable of mobilizing our immune system and provoking an immune response. |
self-antigens | any molecule or chemical group of an organism which acts as an antigen in inducing antibody formation in another organism but to which the healthy immune system of the parent organism is tolerant. |
hapten | a small molecule that, when combined with larger carrier such as a protein, can elicit the production of antibodies that bind specifically to it. or incomplete antigen |
penicillin reaction | binding of penicillin to blood proteins |
B lymphocytes | produce antibodies and oversee humoral immunity |
T lymphocytes | non-antibody-producing lymphocytes that constitute the cell-mediated arm of the adaptive defense system |
immunocompetent | the ability of the body’s immune cells to recognize specific antigens’ reflects the presence of plasma membrane-bound receptors |
antigen-presenting cells (APCs) | in immunity it is used to engulf antigens and then present fragments of the, like signal flags, on their own surfaces where they can be recognized by T cells. |