A&P Chapter 21 Immune System exam questions and answers.docx, Exams of Biology

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A&P Chapter 21 Immune System exam questions and answers two systems of immunity in humans - answer innate system (non- specific) adaptive system (specific) structures of the immune system - answer immune cells, antibodies, chemicals first line of defense - answer innate surface barriers: skin, mucous membranes and their secretions second line of defense - answer innate internal defenses: phagocytes, NK cells, inflammation, antimicrobial proteins, fever third line of defense - answer adaptive humoral immunity: B cells cellular immunity: T cells anatomically, the immune system is a ----- system - answer functional (as opposed to an organ system) skin's action in first line of defense - answer keratin presents a physical barrier skin and vaginal secretions are acidic sebum chemicals are toxic to bacteria mucous membrane's action in the first line of defense - answer mucosa traps microorganisms (digestive, respiratory, urinary and reproductive tracts) stomach lining secretes HCl and digestive enzymes saliva and tears contain lysozyme lysozyme - answer enzyme that destroys bacteria local action in the second line of defnse - answer inflammation the story of inflammation - answer macrophages first to crime scene, release chemicals that induce local vasodilation (causing redness and heat of inflamed area due to extra blood) blood vessel permeability changes, allowing fluid, proteins, clotting factors and antibodies to enter injured tissue, causing edema pain is caused by swelling pressure on nerves and bacterial toxins antimicrobial proteins - answer interferons complement proteins and more! interferons - answer antimicrobial protein that: secreted by viral-infected cells to protect healthy cells (interfere with protein synthesis) complement protein - answer antimicrobial protein that: plasma proteins activated by antibodies or pathogens cause cell lysis amplify inflammation fever - answer abnormally high body temp in response systematically to invading germs what cells cause fever? - answer leukocytes and macrophages secrete pyrogens pyrogens - answer reset the body's thermostat upward (secreted by leukocytes and macrophages) how is moderate fever beneficial? - answer zinc (in liver) and iron (in spleen) are less available for pathogen use increases metabolic rate and tissue repair very high fever can --- - answer denature enzymes the body's thermostat - answer hypothalamus antigen-specific and systemic defense system - answer adaptive immune system the adaptive immune system's memory is dependent on --- - answer meeting an antigen first what amplifies inflammation and activates complement proteins? - answer adaptive immune system antibody-mediated immunity - answer humoral immunity cell-mediated immunity (adaptive) - answer cellular immunity antigens - answer any substance that can activate immune system and provoke a response large, complex molecules not normally found in the body - answer antigens antigens can be: - answer natural or synthetic complete or incomplete complete antigens - answer immunogenic reactive incomplete antigens - answer are not immunogenic can be reactive haptens - answer incomplete antigens where do macrophages hang out? - answer they tend to remain in one organ lymphocyte development - answer immature cells released from bone marrow are essentially identical lymphocytes continue to mature in bone marrow and thymus until --- - answer they are immunocompetent and self-tolerant immunocompetent - answer can recognize its one specific antigen and bind to it self-tolerant - answer don't respond to self-antigens what percentage of lymphocytes pass the tests to leave their development organ? - answer 2% naive - answer immunocompetent and self-tolerant B and T cells are this until they met their antigens for the first time antigen challenge - answer when B and T cells meet their antigens for the first time when do B and T cells differentiate into fully functional cells? - answer when they bind to an antigen in an antigen challenge how many antigen receptors do lymphocytes have? - answer 10,000x why can B and T cells bth respond to the same antigen? - answer because they are responsible for different actions functions of APCs - answer engulf antigens and shred them into peices present antigen fragments to B or T cells, who will deal with those antigens later major APCs - answer macrophages and dendritic cells when is humoral immune response activated? - answer when first antigen challenge is between an antigen and a naive B cell sequence of close selection - answer antigen selects B cells with proper receptors this B cell is stimulated to grow and multiply into identical clones most cells become plasma cells a few become memory cells plasma cells - answer antibody secreting cells derived from B cells memory cells - answer B cells that keep antigen memory for a long time immunological memory - answer primary immune response secondary immune response length of primary immune response (humoral) - answer start 3-6 days after antigen challenge peak 10 days decline within days length of secondary immune response (humoral) - answer peak within 2-3 days and last for weeks to months which humoral immune response is faster and longer-lasting? why? - answer the secondary immune response because memory cell is already in place primary immune response (humoral) includes --- - answer antigen challenge, cell differentiation and proliferation what is active humoral immunity? - answer when B cells encounter antigens and produce antibodies when cellular immunity needed? - answer when antibodies in plasma are useless against antigens within cells types of T cells - answer helper cells - CD4 glycoprotein on plasma membrane cytotoxic cells - CD8 glycoprotein on plasma membrane what cells are important in both cellular and humoral immunity? - answer helper T cells functions of helper T cells - answer help activate macrophages, B and T cells and induce their proliferation help promote B cell antibody production release proteins to recuit more immune cells and amplify innate defenses (they do not attack germs directly) without what cell is there no immune response? - answer helper T cells targets of cytotoxic T cells - answer virus-infected cells, bacteria, parasites, cancers, foreign cells (from blood transfusion of tissue transplant) how to cytotoxic T cells work? - answer they create pores on target cell plasma membrane and enzymes enter and degrade cell contents causes apoptosis