| A | B |
|---|
| ABO blood groups | based on the presence or absence of carbohydrates A and B on the surface of red blood cells |
| acquired immunity | defense that is mediated by B lymphocytes (B cells) and T lymphocytes (T cells) |
| active immunity | immunity from the action of a person’s B cells and T cells and the resulting B and T memory cells specific for a pathogen |
| AIDS (acquired immunodeficiency syndrome) | late stages of HIV defined by a reduction of T cells and the appearance of characteristic secondary infections |
| anaphylactic shock | acute |
| antibody | protein secreted by plasma cells that binds to a particular antigen and marks it for elimination |
| antigen | macromolecule that elicits an immune response by lymphocytes |
| antigen presentation | MHC molecule binds to a fragment of an intracellular protein antigen so it can be recognized by a T cell |
| antigen receptor | surface protein located on B cells and T cells that binds to antigens |
| antigen-presenting cell | ingests bacteria and viruses and destroys them generating peptide fragments displayed to T cells |
| apoptosis | changes that occur within a cell as it undergoes programmed cell death |
| autoimmune disease | disorder in which the immune system turns against self |
| B cell receptor | antigen receptor on B cells containing two antigen-binding sites a.k.a. membrane immunoglobulin |
| B lymphocyte (B cell) | develops to maturity in the bone marrow effector cells of humoral immunity |
| CD4 | surface protein enhances the interaction between the T cell and the antigen-presenting cell |
| CD8 | surface protein on most cytotoxic cells enhances the interaction between the T cell and the target cell |
| cell-mediated immune response | activation of cytotoxic T cells which defend against infected cells cancer cells and transplanted cells |
| chemokin | secreted by many cell types near a site of injury or infection that help direct migration of white blood cells |
| class I MHC molecules | surface proteins encoded by a family of genes called the major histocompatibility complex found on nearly all nucleated cells |
| class II MHC molecules | surface proteins on specialized cell types commonly called antigen-presenting cells |
| clonal selection | antigen selectively binds to and activates only those lymphocytes bearing receptors specific for the antigen |
| complement system | proteins that may amplify the inflammatory response enhance phagocytosis or directly lyse pathogens |
| cytokine | regulate the function of lymphocytes and other cells of the immune system |
| dendritic cell | antigen-presenting cell located mainly in lymphatic tissues and skin |
| effector cell | muscle cell or gland cell that performs the body’s responses to stimuli |
| eosinophil | WBC low phagocytic activity that is thought to play a role in defense against parasitic worms |
| epitope | accessible region of an antigen to which an antigen receptor or antibody binds a.k.a. antigenic determinant |
| graft versus host reaction | attack against a patient’s body cells by lymphocytes received in a bone marrow transplant |
| heavy chain | polypeptide chains that make up an antibody molecule and B cell receptor |
| helper T cell | secretes cytokines that promote the response of B cells and cytotoxic T cells to antigens |
| histamine | released by mast cells that causes blood vessels to dilate and become more permeable during an inflammatory response |
| HIV (human immunodeficiency virus) | infectious agent that causes AIDS |
| humoral immune response | activation of B cells and that leads to the production of antibodies |
| immunization | generating a state of immunity by artificial means |
| active immunization | nonpathogenic version of a normally pathogenic microbe is administered to stimulate T and B cells |
| passive immunization | antibodies specific for a particular microbe are administered |
| immunoglobulin (Ig) | proteins that function as antibodies |
| inflammatory response | localized innate immune defense triggered by physical injury or infection of tissue |
| innate immunity | present before exposure to pathogens and is effective from the time of birth |
| interferon | protein that has antiviral or immune regulatory functions |
| light chain | second type of polypeptide chains that make up an antibody molecule and B cell |
| lymphatic system | system of vessels and lymph nodes separate from the circulatory system that returns fluid proteins and cells to the blood |
| lymphocyte | WBC that mediates acquired immunity |
| lysozyme | enzyme in sweat tears and saliva that attacks bacterial cell walls |
| macrophage | functions in innate immunity by destroying microbes and in acquired immunity as an antigen-presenting cell |
| major histocompatibility complex (MHC) | encode a large set of cell surface proteins called MHC molecules |
| mast cell | produces histamine and other molecules that trigger the inflammatory response |
| membrane attack complex (MAC) | set of complement proteins that forms a pore in the membrane of bacterial and transplanted cells causing the cells to die by lysis |
| memory cell | clone of long-lived lymphocytes formed during the primary immune response |
| monoclonal antibody | antibodies produced by a single clone of cultured cells and thus are all specific for the same antigen |
| monocyte | WBC migrates into tissues and develops into a macrophage |
| natural killer (NK) cell | WBC that can kill tumor cells and virus-infected cells; an important component of innate immunity |
| neutrophil | WBC phagocytic and tend to self-destruct as they destroy foreign invaders |
| passive immunity | conferred by the administration of ready-made antibodies |
| phagocytosis | endocytosis involving large particulate substances accomplished mainly by macrophages neutrophils and dendritic cells |
| plasma cell | antibody-secreting effector cell of humoral immunity |
| primary immune response | initial acquired immune response to an antigen appears after a lag of about 10 to 17 days |
| Rh factor | protein antigen on the surface of red blood cells designated Rh-positive |
| secondary immune response | elicited on second or subsequent exposures to a particular antigen more rapid of greater magnitude and of longer duration |
| T cell receptor | antigen receptor on T cells |
| T lymphocyte (T cell) | develops to maturity in the thymus |
| thymus | small organ in the thoracic cavity of vertebrates where maturation of T cells is completed |
| vaccination | immunization |
