The Immune System Exam Questions Answered Correctly Latest Update 2024 (Already Passed)

The Immune System Exam Questions Answered Correctly Latest Update 2024 (Already Passed) ABO blood groups - Answers Genetically determined classes of human blood; based on the presence or absence of carbohydrates A and B on the surface of red blood cells. The ABO blood group phenotypes, also called blood types, are A, B, AB, and O. acquired immunity - Answers The kind of defense that is mediated by B lymphocytes (B cells) and T lymphocytes (T cells). It exhibits specificity, memory, and self-nonself recognition. Also called adaptive immunity. active immunity - Answers Long-lasting immunity conferred by the action of a person's B cells and T cells and the resulting B and T memory cells specific for a pathogn. Active immunity can develop as a result of natural infection or immunization. AIDS (acquired immunodeficiency syndrome) - Answers The name of the late stages of HIV infection, defined by a specified reduction of T cells and the appearance of characteristic secondary infections. anaphylactic shock - Answers An acute, whole-body, life-threatening, allergic response. antibody - Answers A protein secreted by plasma cells (differentiated B cells) that binds to a particular antigen and marks it for elimination; also called immunoglobulin. All antibody molecules have the same Y-shaped structure and in their monomer form consist of two identical heavy chains and two identical light chains joined by disulfide bridges. antigen - Answers A macromolecule that elicits an immune response by lymphocytes. antigen presentation - Answers 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 is displayed and can be recognized by a T cell. antigen receptor - Answers The general term for a surface protein, located on B cells and T cells, that binds to antigens, initiating acquired immune responses. The antigen receptors on B cells are called B cell receptors (or membrane immunoglobulins), and the antigen receptors on T cells are called T cell receptors. antigen-presenting cell - Answers A cell that ingests bacteria and viruses and destroys them, generating peptide fragments that are bound by class II MHC molecules and subsequently displayed on the cell surface to helper T cells. Macrophages, dendritic cells, and B cells are the primary antigen-presenting cells. apoptosis - Answers The changes that occur within a cell as it undergoes programmed cell death, which is brought about by signals that trigger the activation of a cascade of suicide proteins in the cell destined to die. autoimmune disease - Answers An immunological disorder in which the immune system turns against self. B cell receptor - Answers The antigen receptor on B cells: a Y-shaped, membrane-bound molecule consisting of two identical heavy chains and two identical light chains linked by disulfide bridges and containing two antigen-binding sites; also called a membrane immunoglobulin or membrane antibody. B lymphocyte (B cell) - Answers A type of lymphocyte that develops to maturity in the bone marrow. After encountering antigen, B cells differentiate into antibody-secreting plasma cells, the effector cells of humoral immunity. CD4 - Answers A surface protein, present on most helper T cells, that binds to class II MHC molecules on antigen-presenting cells, enhancing the interaction between the T cell and the antigen-presenting cell. CD8 - Answers A surface protein, present on most cytotoxic cells, that binds to class I MHC molecules on target cells, enhancing the interaction between the T cell and the target cell. cell-mediated immune response - Answers The branch of acquired immunity that involves the activation of cytotoxic T cells, which defend against infected cells, cancer cells, and transplanted cells. class I MHC molecules - Answers A collection of cell surface proteins encoded by a family of genes called the major histocompatibility complex. Class I MHC molecules are found on nearly all nucleated cells. class II MHC molecules - Answers A collection of cell surface proteins encoded by a family of genes called the major histocompatibility complex. Class II MHC molecules are restricted to a few specialized cell cell types, commonly called antigen-presenting cells (dendritic cells, macrophages, and B cells). clonal selection - Answers The process by which an antigen selectively binds to and activates only those lymphocytes bearing receptors specific for the antigen. The selected lymphocytes proliferate and differentiate into a clone of effector cells and a clone of memory cells specific for the stimulating antigen. Clonal selection accounts for the specificity and memory of acquired immune responses. complement system - Answers A group of proteins that complement the antibodies and phagocytic cells; assists in ridding an organism of microbes and damaged cells; promotes inflammation. cytokine - Answers Any of a group of proteins secreted by a number of cell types, including macrophages and helper T cells, that regulate the function of lymphocytes and other cells of the immune system. epitope - Answers A small, accessible region of an antigen to which an antigen receptor or antibody binds; also called an antigenic determinant. helper T cell - Answers A type of T cell that, when activated, secretes cytokines that promote the response of B cells (humoral response) and cytotonic T cells (cell-mediated response) to antigens. histamine - Answers A substance released by mast cells that causes blood vessels to dilate and become more permeable during an inflammatory response. HIV (human immunodeficiency virus) - Answers The infectious agent that causes AIDS. HIV is a retrovirus. humoral immune response - Answers The branch of acquired immunity that involves the activation of B cells and that leads to the production of antibodies, which defend against bacteria and viruses in body fluids. immunization - Answers The process of generating a state of immunity by artifical means. Active immunization: nonpathogenic version of a normally pathogenic microbe is administered, inducing B and T cell responses and immunological memory. Passive immunization: antibodies specific for a particular microbe are administered, conferring immediate but temporary protection. immunoglobulin (Ig) - Answers Any of the class of proteins that function as antibodies. Immunoglobulins are divided into five major classes that differ in their distribution in the body and antigen disposal activities. inflammatory response - Answers A localized innate immune defense triggered by physical injury or infection of tissue in which changes to nearby small blood vessels enhance the infiltration of white blood cells, antimicrobial proteins, and clotting elements that aid in tissue repair and destruction of invading pathogens; may also involve systemic effects such as fever and increased production of white blood cells. innate immunity - Answers The kind of defense that is mediated by phagocytic cells, antimicrobial proteins, the inflammatory response, and natural killer (NK) cells. It is present before exposure to pathogens and is effective from the time of birth. interferon - Answers A protein that has antiviral or immune regulatory functions; secreted by virus-infected cells to help nearby cells resist viral infection lymphatic system - Answers A system of vessels and lymph nodes, separate from the circulatory system, that returns fluid, proteins, and cells to the blood.