Exam 3 Review:  Chapter 21:  General Terms

immunology - The branch of biology and biomedicine concerned with the structure and function of the immune system, innate and acquired immunity, the bodily distinction of self from nonself, and laboratory techniques involving the interaction of antigens with specific antibodies.

immunogenicity - The property of being able to evoke an immune response within an organism; it depends partly on the size of the size and complexity of the substance (antigen) in question and partly on how unlike the substance is in comparison to the host's molecules (self-antigens).

immune specificity - The central property of the immune system which is its ability to respond to a vast array of substances (antigens) individually by the production of responsive clones of activated and memory lymphocytes which generate the various defenses against the antigen; the key to the individualized response is the combination of a genetic library capable of elaborating individual responsive molecules, e.g., specific antibodies, and a genetic library, the Major Histocompatibility Complex, capable of elaborating the array of cell surface markers which allow immune cells to recognize and cooperate with each other and to be able to distinguish foreign from self molecules.  [Note:  The ability of the immune system to respond to an antigen exists before it ever encounters that antigen.]

immunological memory - The property of the immune system which is its ability to respond to an antigen more rapidly and with greater efficiency in second and subsequent encounters with the antigen; the memory response reflects the presence of a small population of T and B lymphocytes, referred to as "memory cells," which differentiated during the initial = primary response to the antigen; although the "memory" lymphocytes did not participate directly in the immune defenses in the primary response, they are present and capable of immediate response, including proliferation and differentiation into active subclones of specific B and T lymphocytes in each subsequent encounter with the particular antigen.  See diagram of primary and secondary ("memory") response for antibody production below.

immunocompetence - The property of the immune system which is its normal capacity to develop a strong, effective immune response following exposure to an antigen.

pathogen - Any living microorganism which has the potential to cause disease, e.g., viruses, bacteria, fungi, protozoans and certain worms.

resistance (to disease) = nonspecific resistance - The general term for all body defenses against injury and disease which are non-specific in the sense of not being generated in response to specific foreign antigen(s); examples include surface barriers (skin and mucous membranes) and their protective secretions (sweat and sebum, cerumen, tears, saliva, the acidity of urine, vaginal and gastric secretions), the processes of vomiting (to expel toxins), inflammation, phagocytosis, and fever, various antimicrobial  proteins (lysozyme, complement, transferrins, interferons) and mediators of inflammation and fever (histamine, kinins, protaglandins, leukotrienes, etc.) and the actions of Natural Killer (NK) lymphocytes.

susceptibility (to disease) - The property of an individual, an organ system, organ or tissue to be affected by disease; it is affected by environmental factors as well as genetic, developmental, and nutritional factors which lower one's resistance.

immunity - Inherited, acquired, or induced resistance to infection by a specific pathogen.

abscess - A localized collection of pus in any internal part of the body (not on a surface such as the skin or a mucous membrane), formed by tissue disintegration and surrounded by inflamed tissue, and, perhaps, walled off by scar tissue.  [An abscess in the dermis is called a "boil."]

cerebral abscess	subcutaneous abscesses

ulcer - A crater-like lesion of the skin or a mucous membrane, e.g., the linings of the respiratory, gastrointestinal, and urogenital systems, which is accompanied by formation of pus and necrosis and sloughing of surrounding tissue, usually resulting from inflammation or ischemia.

cutaneous ulcer	gastric ulcer

metastasis - A secondary cancerous growth formed by transmission of cancerous cells from a primary growth (original site) to one or more sites elsewhere in the body, usually by way of the blood vessels or lymphatics; the potential for metastasis is a characteristic of almost all malignant cancers.

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