Immunology The Immune System test questions and answers.docx, Exams of Biology

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Immunology: The Immune System test questions and answers The Role of the Immune System - answer 1) Defends against invaders (external and internal) 2) Distinguishes self from non-self 3) Discriminates between potentially harmful and nonharmful agents 4) Recalls previous encounters with the same agents 5) Mounts an effective response Name the three types of phagocytic cells. - answer 1) Monocytes/Macrophages 2) Granulocytes (neutrophils, eosinophils, basophils) 3) Dendritic cells (antigen present cells - APC) Which phagocytic cells engulfs the antigen and takes it to the lymph system to activate the Adaptive immune response? - answer Dendritic cells - these are the bridge between innate and adaptive immunity Which cells mediate the humoral immunity response and produce antibodies? - answer B Lymphocytes What is the humoral immunity response (brief overview)? - answer - there are tons of B lymphocytes waiting around to be activated - produce antibodies against antigens - these cells have a memory component (subsequent exposures = quicker reaction) Which cells are involved in the cell-mediated immunity response? - answer T lymphocytes - they need antigen present cells to activate them - includes Helper T cells and cytotoxic T cells Natural Killer (NK) Cells are part of which immune response - answer Innate Immunity What is the role of the NK cells? - answer - recognize abnormal cells (e.g. cancer) - recognize cells that have intracellular pathogens in them (e.g. viruses) - NKs either kill these cells or have no response If an antigen makes it to the blood stream, what organ is responsible for finding it and removing it? - answer Spleen What is the role of the spleen? - answer filters antigens from the blood and is important in the response to systemic infection What happens in the Red pulp in the spleen? - answer dead and dying RED blood cells are removed form circulation in this area What is in the white pulp in the spleen? - answer contains B and T lymphocytes with lots of macrophages and dendritic cells Non-encapsulated lymphoid tissue located on membranes of resp, digestive, and GU tracts is called... - answer mucosa-assoicated lymphoid tissue What cells in the immune system are located in the mucosa-associated lymphoid tissue? - answer lymphocytes, macrophages, dendritic cells, and plasma cells Where does immunity start and why? - answer At the mucosa- associated lymphoid tissue - because there are lots of organisms at these sites The complement system consistes of... - answer a group of proteins normally present in circulation as functionally inactive precursors True/False. Complement proteins can be activated in any random order - answer False. They must be activated in the proper sequence. What process is induced when complement proteins are activated? - answer Inflammation What do inhibitor proteins in "self" cells do to the complement system? - answer They regulate it - prevent uncontrolled activation The complement system produces products that have what type of enzyme activity? - answer proteolytic "OIL" acronym for the complement system - answer O - opsonization I - inflammatory response L - lysis What is opsonization? - answer acts like glue to attach antigens or antigen antibody complexes to macrophages or neutrophils for better phagocytosis - it's the salad dressing! What type of lysis occurs in the complement system? - answer bacterial lysis What are the three pathways to the complement system? - answer 1) alternative 2) classical 3) lectin How are these three pathways the same? - answer they all lead to the activation of a C3 convertase enzyme which cleaves C3 and starts the reaction How are these three pathways different? - answer Alternative - no antibodies needed - it's the innate immune response Classical - uses the antigen-antibody complex = it's the adaptive immune response Lectin - activates Classical but with no antibody Cytokine review! What do they do? - answer - mediate cell actions in innate and adaptive immunity - act locally or systemically What cells are make up the lymphocytic cells of the lymphoid lineage? - answer NK cells T cells B cells Which cell makes plasma cells? - answer B cells True/False: the point of innate immunity is to cause inflammation and nothing else. - answer False. It causes inflammation and also alerts the adaptive immune response What response is our first line of defense? - answer Innate immunity True/False: The innate immune system response only to microbes. - answer True True/False: The innate immune system is sensitive but not specific - answer True - it responds the same way to all microbes True/False. Some of the players in the innate immune response have to be made so it takes time before they start working - answer False - the players in the innate immune response are already in place waiting to go What are the players of the innate immunity? - answer 1) epithelial barriers 2) phagocytic cells (neutrophils, basophils, eosinophils) 3) NK cells 4) Complement system & inflammatory system 5) cytokines (regulate and coordinate the system) Epithelial barrier in the innate immune system are... - answer skin and mucous membranes Innate immunity cells recognize two things for pathogen recognition...what are they? - answer 1) patterns on the microbe (pathogen associated molecular patterns) 2) host receptors (e.g. pattern recognition, toll-like, and scavenger receptors) What are the soluble mediators of the innate immunity response? - answer 1) Opsonins - tag microorganisms 2) cytokines 3) complement proteins In order for the Innate system to activate the adaptive system, there are two signals needed: - answer 1) antigen 2) reaction to the antigen The second signal, "reacting to the antigen", can be done by one of two ways - answer 1) antigen-presenting dendrites 2) activation of the complement system True/False: Adaptive Immunity is acquired and specific - answer True Responds to microbes and non-microbes, but it can distinguish between different ones What are the two types of adaptive immunity? - answer 1) Humoral Immunity - B lymphocytes 2) Cell-mediated Immunity - T lymphocytes The role of the humoral immunity is to... - answer defend against extracellular microbes and toxins humoral = fluid (B cells are out floating around looking for toxins) The role of cell-mediated immunity is to... - answer defend against intracellular microbes like viruses T cells target cells that have been compromised (that's why it's called cell-mediated) - activate CD8 T cells Remember: V18, viral, Class 1, CD8 What is the purpose of MHC-2? - answer - associated with engulfed particles (epitopes) - recognized by CD4 T cells Remember: APC, Class 2, CD4 The MHC molecules are associated with which immunity response? - answer Cell-Mediated Adaptive Response What is the role of T cells? - answer to protect against viruses, cancers, and intracellular bacteria True/False - T cells can only recognize membrane bound antigens - answer True Cytotoxic T cell (CD8) - answer - kills the cells that have been damaged from within (cancer, virus, etc.) - These affected cells show different receptors (MHC 1) which signal cytotoxic T cells to kill them Helper T cell (CD4) - answer - get activated by the immune response - attach to the MHC 2 receptors and release cytokines - stimulates the inflammatory response - stimulates B cells and plasma cells - stimulate B and T helper memory cells - activates cytotoxic T cells B cells can be identified by membrane receptors. What receptors do they have? - answer 1) immunoglobulin (antigen receptors) 2) Class 2 MHC proteins 3) Complement receptors 4) specific CD molecules True/False - every B cell has a unique receptor and antibody so it's very specific - answer True More about B cells - answer - stimulated by CD4 helper T cells to proliferate and differentiate into plasma cells (so antibodies can be made) - when a "new" antigen is seen, they produce a plasma cell that produces an antibody PLUS a new unique memory B cell that can produce antibody more quickly the next time the antigen presents Several things can happen when antibodies bind to the antigen: - answer 1) antigen/antibody complexes 2) agglutination of clumping of cells 3) neutralization of bacteria toxins and viruses 4) lysis or destruction of pathogens/cells 5) adherence of antigen to immune cell 6) facilitation of phagocytosis 7) complement activation Primary vs. Secondary B Cell response - answer Primary - first time an antigen is seen - small reaction that takes longer since antibodies have to be produced Secondary - subsequent exposures- greater reaction every time - quicker response because antibodies are ready and waiting IgG - answer Most prevalent - displays antiviral, antibacterial, and antitoxin properties - activates complement and binds to macrophages - can cross placenta - protects newborns IgA - answer - body secretions (saliva, nasal, resp, breast milk) - protects mucous membranes IgM - answer - forms natural antibodies (e.g. ABO blood type)