| Term | Definition |
|---|
| INNATE IMMUNITY | unspecific immunity that is present at birth (skin, mucous, chemical defenses) |
| ACQUIRED IMMUNITY | specific immunity that develops after expsoure to foreign substances |
| LYMPHOCYTE | white blood cell that can produce two types of immune responses |
| ANTIBODY | produced by a B-lymphocyte in the humoral response; is a defensive protein that binds to microbes and mark them for elimination |
| CELL-MEDIATED RESPONSE | cytotoxic lymphocytes directly destroy infected body cells, cancer cells, or foreign tissue |
| LYSOZYME | an enzyme that digests cell walls of bacteria; present in saliva, tears, mucous secretions in the upper respiratory tract and eyes |
| PHAGOCYTOSIS | ingestion of microorganisms by certain white blood cells (phagocytes) that produce antimocrobial proteins and start inflammation |
| NEUTROPHIL | 60-70% of all white blood cells; self-destruct when it performs phagocytosis |
| MACROPHAGE | large, long-lived cell that develops from a monocyte; stays in the sleep and lymph nodes |
| MONOCYTE | 5% of circulating white blood cells; turns into a macrophage |
| EOSINOPHIL | attacks multicellular parasites; secretes enzymes that attack the parasite rather than digests it; not too common |
| DENDRITIC CELL | ingests microbes but focuses more on acquired immunity |
| COMPLEMENT SYSTEM | a system made of 30 serum antimicrobial proteins that, when activated, will lyse pathogenic cells |
| INTERFERON | protein secreted by cells infected by viruses; it initiates an innate response by nearby cells so that they will produce substances that stop viral reproduction |
| INFLAMMATORY RESPONSE | damaged tissue will cause many chemical signals to be released |
| HISTAMINE | a chemical that is part of the inflammatory response; dilates blood vessels so that more blood can flow to the injured site (swelling) |
| MAST CELL | a cell that stores histamine; located in connective tissues |
| CHEMOKINE | a small protein that directs the migration of phagocytes toward an infected cell and signals them to increase productionf of microbe-killing compounds; part of the inflammatory response |
| NATURAL KILLER CELL | an innate defense cell of vertebrates; it patrols the body and attacks virus-infected or cancer cells; it has receptors that can recognize general features on the surfaces of its targets; kills cells by apoptosis |
| APOPTOSIS | programmed cell death |
| CYTOKINE | secreted by macrophages and dendritic cells; activates lymphocytes and other cells |
| ANTIGEN | any foreign molecule that lymphocytes recognize and respond to |
| EPITOPE | a small, accessible region of an antigen to which an antigen receptor or antibody binds; also called an antigenic determinant |
| B LYMPHOCYTE | a lymphocyte that matures in the bone marrow; after encountering an antigen, it will differentiate into antibody-secreting plasma cells (effector cells of humoral immunity) |
| T CELL | a lymphocyte that matures in the thymus; it will start cell-mediated immunity when it encouters an anitgen |
| ANTIGEN RECEPTOR | a surface protein on a B/T lymphocyte that starts acquired immune responses |
| B CELL RECEPTOR | Y-shaped receptor that is made of 4 polypeptide chains: 2 identical heavy chains and 2 light chains linked by disulfide bridges; recognizes intact antigens |
| HEAVY CHAIN | a polypeptide chain that is made of a variable region that contributes to the antigen-binding site and a constant region |
| LIGHT CHAIN | a polypeptide chain that is made of a variable region that contributes to the antigen-binding site and a constant region |
| IMMUNOGLOBULIN | a secreted antibody that is similar to B-cell receptors that isn't bound to a transmembrane |
| T CELL RECEPTOR | a receptor that has 2 different polypeptide chains (a and B) linked by a disulfide bridge; recognizes fragments of antigens boudn to MHC molecules |
| MAJOR HISTOCOMPATIBILITY COMPLEX | A family of genes that encode a large set of cell surface proteins called MHC molecules. Class I and class II MHC molecules function in antigen presentation to T cells. Foreign MHC molecules on transplanted tissue can trigger T cell responses that may lead to rejection of the transplant. |
| ANTIGEN PRESENTATION | the process by which an MHC molecule binds to a fragment of an intracellular protein antigen and carries it to the cell surface, where it can be recognized by a T cell |
| CYTOTOXIC T CELL | a lymphocyte that, when activated, kills infected cells, cancer cells, and transplanted cells; can recognize Class I MHC molecules |
| ANTIGEN-PRESENTING CELL | dendretic cell, macrophase, B cell; dislays internalized antigens to helper T cells |
| THYMUS | a gland in the thoracic cavity above the heart |
| EFFECTOR CELL | a muscle or gland cell that resonds to stimuli ; short-lived daughter cell of lymphocytes |
| MEMORY CELL | long-lived daughter cell of lymphocytes; has receptors that are specific for the antigen that caused the mother cell to clone itself |
| CLONAL SELECTION | antigens bind to specific receptors, causing a fraction of lymphocytes to clone themselves |
| PRIMARY IMMUNE RESPONSE | the acquired immune response to an antigen, which appears after a lag of about 10 to 17 days |
| PLASMA CELL | generated by B cells; an antibody-secreting effector B cell |
| SECONDARY IMMUNE RESPONSE | a fast immune response that appears in 2 - 7 days |
| HUMORAL IMMUNE RESPONSE | acquired immune response that involves the activation of B cells and that leads to the production of antibodies in body fluids |
| CELL-MEDIATED IMMUNTE RESPONSE | acquired immune response where cytotoxic T cells are cloned and destroy target cells |
| HELPER T CELL | a cell that responds to peptide antigens displayed on antigen-presenting cells and stimulates the activation of nearby B cells and cytotoxic T cells |
| CD4 | a surface protein on helper T cells that binds the class II MHC molecule |
| CD8 | a surface protein on cytotoxic T cells that binds the cell to a target cell |
Combine with other sets
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