All of the following except ____ is a function of the lymphatic system. 1. Production, maintenance, and distribution of lymphocytes 2. Resisting and overcoming disease 3. Draining lymph from the bone marrow 4. Maintain normal blood composition and volume Which of the following is true of lymphatic capillaries? 1. They have smaller diameters than blood capillaries. 2. Endothelial cells of lymphatic capillaries are not bound tightly together, but they do overlap. 3. They have thicker walls than blood capillaries. 4. They form continuous tubes. Which of the following is a dangerous consequence of lymphedema in a limb? 1. Accumulation of toxins and pathogens due to stagnant interstitial fluids 2. Swelling and distension of the limb 3. Loss of elasticity in connective tissue of the affected limb 4. All of the above are correct If the thymus failed to produce thymic hormones, which population of lymphocytes is affected? 1. 2. 3. 4. B lymphocytes T lymphocytes Monocytes Antigen-producing cells Why do lymph nodes enlarge during some infections? 1. 2. 3. 4. Because of bacterial invasion and accumulation Due to accumulation of antibodies Due to accumulation of circulating T cells Due to phagocytic and lymphatic cell division After splenectomy, which immune functions become impaired? 1. Initiation of immune response by B cells and T cells in response to antigens 2. Phagocytosis of damaged or infected cells circulating in blood 3. Complement activation 4. 1 and 2 are correct Which of the following is not a characteristic or function of nonspecific defenses? 1. 2. 3. 4. Are present at birth Destruction of abnormal cells by NK cells Dependence on the activity of lymphocytes Interferons coordinating defenses against viral infections Why would the liver, lungs, and CNS be affected by a low monocyte count in blood? 1. Kupffer cells, alveolar macrophages, and microglia are derived from monocytes. 2. Lack of monocytes causes NK lymphocytes to attack those structures. 3. The liver, lungs and CNS are secondary parts of the immune system. 4. None of the above is correct. How do interferons increase resistance to viral infections? 1. They can respond immediately. 2. They recognize abnormal cells by the presence of unusual antigens. 3. They interfere with viral replication inside cells. 4. All of the above are correct. What effects do pyrogens have in the body? 1. 2. 3. 4. Release complement Increase temperature/cause fever Stimulate NK cells Release interferon All of the following except ____ is an effect of complement activation. 1. 2. 3. 4. Making target cells easier to engulf Destruction of target cell membranes Attracting neutrophils and macrophages Reducing inflammation Why is having both cell-mediated and antibodymediated immunity integral to a healthy immune system? 1. 2. 3. 4. T cells defend against pathogens inside cells, while B cells defend against antigens in body fluids. Cell-mediated immunity is genetically determined, while antibody-mediated immunity is acquired. Cell-mediated immunity is “specific”, while antibodymediated immunity is “non-specific”. None of the above is correct. Induced passive immunity ____, while induced active immunity ____. 1. 2. 3. 4. Is genetically determined/is conferred by administration of antibodies Answer: Is conferred from mother to infant through breast milk/ develops after exposure to antigens in the environment Is conferred by administration of antibodies/develops after administration of an antigen to prevent disease Stimulates antibodies against something you might encounter in the future/combats something you’ve already been exposed to If “tolerance” breaks down, what is the potential result? 1. 2. 3. 4. Lymphocytes divide to produce clones of themselves. Lymphocytes would not “remember” an antigen they previously encountered. The immune system would not be prepared to attack certain antigens. B cells and T cells could attack normal antigens. How can the presence of an abnormal peptide in the cytoplasm of a cell initiate an immune response? 1. 2. 3. 4. By stimulating production of pyrogens, beginning an immune response By becoming attached to B cells, which launch an immune response By becoming attached to MHC and being presented to T cells By altering the genetic programming of an infected cell A decrease in the number of cytotoxic T cells directly affects which type of immunity? 1. 2. 3. 4. Acquired immunity Innate immunity Humoral immunity Cell-mediated immunity How does the absence of helper T cells affect the antibody-mediated immune response? 1. Neither B cells nor T cells are stimulated to respond to a pathogen, therefore no immune response occurs. 2. Cytotoxic T cells proliferate. 3. Class II MHC proteins appear in the cell membrane. 4. Immune response is unaffected by loss of helper T cells. What does an elevated number of plasma cells indicate? 1. The cascade of events causing B cell activation has occurred. 2. Antibodies to a pathogen are diminishing. 3. CD4 cells have been activated. 4. 1 and 3 are correct Which analogy is most appropriate for comparing the interaction of an antibody’s active site binding with an antigen? 1. The heavy-chain constant segment’s interaction with the light chain of an antibody 2. A drug reaction, such as penicillin allergy 3. An enzyme interacting with a substrate molecule 4. The binding of a hapten and a carrier molecule The formation of an antigen-antibody complex may cause elimination of the antigen in what way? 1. An antibody binds to a site on a virus making the toxin incapable of attaching itself to a cell. 2. An antibody binds to antigenic determinant sites on two different antigens. 3. Antigens covered with antibodies attract phagocytes. 4. All of the above are correct. How is the secondary response affected if memory B cells for a particular antigen are absent? 1. A pathogen that had previously invaded would be recognized and killed quickly. 2. The secondary response would not occur. 3. Memory T cells take over the role of the memory B cells. 4. CD4 cells would differentiate into B cells. Which kind of immunity protects a developing fetus, and how is that immunity produced? 1. Natural active immunity; maternal illness and recovery 2. Natural passive immunity; the product of IgG antibodies 3. Artificial passive immunity; injections of gamma globulins 4. Artificial active immunity; vaccinations Which of the following correctly describes the sequence of WBCs responsible for overcoming a bacterial infection? 1. Neutrophils and NK cells/phagocytes/ cytotoxic T cells/plasma cells 2. Memory B cells/plasma cells/NK cells 3. Phagocytes/plasma cells/antibodies 4. B cells/helper T cells/phagocytes/CD8 cells Which of the following conditions can be determined with a skin test? 1. If a baby has severe combined immunodeficiency disease 2. If a person has been exposed to an antigen 3. If a person has an autoimmune disease 4. If a person has diabetes mellitus Denise is allergic to pollen. What is an allergy and how is allergy to pollen classified? 1. 2. 3. 4. Results from treatment with immunosuppressive agent/delayed hypersensitivity Develops when the immune response targets normal body cells/cytotoxic reaction An inappropriate or exaggerated immune response/immediate hypersensitivity Results from problems of development of lymphoid organs/immune complex disorder How does increased stress decrease the effectiveness of the immune response? 1. By burning energy needed for immunity 2. By inhibiting interleukin secretion 3. By depressing the inflammatory response 4. 2 and 3 are correct