HSC 4504 Final Exam PH Immunology 2024 Actual 50 Questions and Answers Solved/Verified 100%

HSC 4504 Final Exam PH Immunology 2024 Actual 50 Questions and Answers Solved/Verified 100% Which of the following is TRUE about innate immunity? Innate immunity improves with successive exposures to the same pathogen or antigen. Innate immunity employs B and T lymphocytes to generate a response. Innate immunity employs phagocytes and natural killer cells to generate a response. Innate immunity is specific for any given pathogen or antigen. Innate immunity has a stronger secondary response than a primary response to an antigen. True False Infection by a respiratory virus produces? Active immunity Passive immunity Either active or passive immunity None of the above The body produces its own antibodies with which form of immunity? Passive immunity Active immunity Both passive and active immunity None of the above Correct. Immune responses normally occur in primary lymphoid organs. True False The thymus increases in size as we grow older. True False Both positive and negative selection can occur in the thymus. True False Immune cells can respond to foreign antigens that enter a lymph node. True False An individual can live a normal life without functional bone marrow. True False Intracellular organisms may survive inside of macrophages. True False is the most abundant complement protein and is important in all three complement pathways. C9 C4 C3 C6 Correct. The classical pathway is part of the innate immune response and can be activated directly by microorganisms. True False IgM and/or IgG are required for the activation of the alternative pathway. True False C3b and C5b are complement fragments that assist in which of the following defense mechanisms? Phagocytosis Endocytosis Cell lysis None of the above The formation of the complement membrane attack complex (small round bubbles on surface of bacteria) kills the cell by ? antigen mediated cell death. antibody dependent cell death. accumulation of protein in the cell membrane. creating pores in the cell membrane. Inflammation is an innate nonspecific reaction that helps the immune response. True False Question 17 0.7 / 0.7 pts Chronic inflammation is exudative in nature. True False An inflammed area described as "calor" is? painful hot to the touch very red swollen Similarities of T­cell receptors and B­cell receptors include? Great diversity of the receptors Both receptors are released into the blood Receptors are composed of polysaccharide All of the above Correct. Antibodies are protective against both intracellular and extracellular pathogens. True False B cells are primarily located in the bone marrow, spleen, and lymph nodes, where they can interact with antigens. True False Protection from autoimmunity is the primary function of antibodies. True False Isotype switching is the production of a different heavy chain class by B­cells during differentiation. True False Correct. Fab regions of antibodies bind? Antigen Complement Phagocytes All of the above Correct. If an individual is atopic, which antibody class would you expect to see increased? IgM IgG IgE IgA Correct. What neutralizing antibody class rises in the secondary immune response and can remain elevated for life? IgM IgG IgA IgE None of the above Isotype switching is usually IgG to IgM. True False Maternal antibodies passed to an infant are IgM. True False The increase in the strength of the antigen­binding capability of an antibody after repeated antigen exposure is known as? Avidity Affinity maturation Anergy None of the above Correct. An epitope must be bound to a MHC molecule to be recognized by a T­cell receptor. True False T­independent antigens produce isotype switching and affinity maturation than T­ dependent antigens. More, more More, less Less, more Less, less Correct. Superantigens can produce mass activation of macrophages. True False Why are second signals expressed by antigen­presenting cells? To avoid attack by NK cells To signal infection by viruses To ensure adaptive immune responses against only microbes All of the above Incorrect. Most regulatory T­cells are? CD4+ CD8+ Equally CD4+ and CD8+ Lacking either CD4 or CD8 Correct. Antigen­presenting cells present peptides derived from proteins on MHC Class II molecules. Extracellular Intracellular Both extracellular and intracellular None of the above Correct. The activation of by requires CD40 and Interferon­gamma. B­cells, Th1 cells Macrophages, Th1 cells T­cells, macrophages NK cells, macrophages Correct. Cytokines must be in high concentration for a cellular response to occur. True False Which of the following statements about cytokines are FALSE? Cytokines are low molecular weight proteins. Cytokines are important in nearly all biologic processes, such as cell growth, inflammation, and tissue repair. Cytokines have multiple functions. Cytokines are mediators of both adaptive and innate immunity. None of the above Mature B­cells that are repeatedly exposed to high levels of self­antigens in the peripheral lymphoid tissues become? Overreactive Anergic Unaffected by the self­antigens Response is dependent on the tissue type and type of self­antigen Correct. Myasthenia gravis is an example of an autoimmune disease. True False Correct. Pollen can quickly cause an immune response when the body produces IgE antibodies to these pollen antigens. What type of hypersensitivity reaction does this describe? Type I Type II Type III Type IV Mast cells may release during immediate hypersensitivity. Histamine Leukotrienes Prostaglandins All of the above Incorrect. Type II hypersensitivity reactions involve? Immune complexes IgG IgE CD4+ cells Correct. Primary immunodeficiencies are caused by infectious agents and are contagious to others. True False Secondary immunodeficiencies may be caused by all of the following EXCEPT: infection malnutrition genetic defects chemotherapy or radiation treatments for cancer splenectomy This type of primary immunodeficiency is rare except when consanguinity is involved. Patients with this disease have decreased activity of an enzyme that helps cells remove toxic byproducts of metabolism from cells, resulting in the death of immune cells. What disease am I? RAG deficiency ADA deficiency LAD DiGeorge Syndrome Type 3 hypersensitivity can result in damage to joints. True False Delayed­typed hypersensitivity is a reaction? Type I Type II Type III Type IV Correct. Which form(s) of donor organ rejection are mediated by antibodies? Accelerated Hyperacute Chronic Acute Only hyperacute and accelerated rejection are mediated by antibodies. Direct antigen recognition is responsible for acute organ rejection. True False