Immune system responses

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Immune system responses
2015-11-09 18:02:47
Micribiology Specific Nonspecific Immune Response
Micro lecture exam 3
EZ book and lecture
Show Answers:

  1. Your skin , mucous membrane, phagocytosis and inflammtion are considered ____ (specific/nonspecific) defenses of your body against pathogenic microbes.
  2. Explain how the mucous membrane in your lower respiratory tract get rid of microbes entering your body. (Also explain the importance of mucus in the mucous membrane as we breath in)
    • Mucus is a thick substance that traps microbes as they are in inhaled or eaten.
    • Our lower respiratory tract have something called the ciliary escalator, which are rows of cilia that sweep microbe-laden mucous toward the throat where it can be coughed out of the body.
  3. What is mechanical washing and what are some examples?
    • Mechanical washing is when microbes are removed from mucous membranes by secretions of the body.
    • Examples include:
    • Tears
    • Saliva
    • Urine
    • Vaginal secretions
  4. Many physical secretions of the human body (tears and saliva for example) include this enzyme, which breaks down the peptidoglycan and cause lysis of bacteria.
  5. List the major nonspecific defenses of our body
    • 1. Skin
    • Including the epidermis and mucous membrane
    • 2. Mucus (captures microbes)
    • 3. Cilia that sweep the mucus up the respiratory tract
    • 4. Body secretions including: tears, saliva, sweat, etc.
    • 5. Lysozyme enzymes included in secretions that lyse the cell
    • 6. Body temp
    • 7.. pH in our stomach cid
    • 8. WBCs
    • 9. Phagocytosis
    • 10. Fever 
    • 11. Inflammation
    • 12. Interferons
  6. This hormone is released when cells are damaged, which increase vasodilation and blood vessel permeability. What is the name of this hormone, the name of the action, and its purpose?
    HIstamine is released, which is what causes inflammation: the purpose is to allow greater blood flow, which delivers phagocytes and jclotting elements such as fibrinogen.
  7. What are the benefits of inflammation to protect against pathogens?
    • Histamine increases vasodilation and blood vessel permeability.
    • This delivers phagocytes to the injured area, and cells exposed to pathogens
    • Fibrinogen is also released, which creates blood clots to wall off pathogens.
  8. How does fever affect iron away from microbes that need it for growth?
    A higher body temp causes cells to release transferrins, that tightly binds iron and keeps it way from microbes.
  9. What is Interleuken-1 (IL-1) and how does it effect the body?
    • This is a cytokine released by phagocytes that signal the hypothalamus to raise the body temp. 
    • It also leads to increased production of T-lymphocytes
  10. This type of defense protein is produced by fibroblasts in CT and leukocytes, when  cell is infected by a virus. 
    How do these proteins help our immune system?
    • Interferons: Alpha- and Beta-
    • After a cell is infected, they leave the cell and travel to neighboring cells' receptors, signling them to produce antiviral proteins (AVP)
  11. T or F: Alpha and Beta interferons do not help the originally virus infected cell
    True: They only travel to neighboring cells to warn have them produce antiviral proteins.
  12. What produces Gamma-proteins and what is its purpose?
    • Activated Lymphocytes tht have encountered microbes. 
    • It signals phagocytes, causing them to kill bacteria.
  13. Define acquired immunity and active immunity?
    List the 3 types of active immunity
    • Acquired immunity: Resistance to specific pathogens
    • Active immunity: Any time our immune system responds to a pathogen. 
    • The 3 types are:
    • 1. Naturally acquired: immunity triggered in response to an infection
    • 2. Artificially acquired: triggered by a vaccine
    • 3. Passive Immunity: receiving antibodies from someone else (breast-fed babies)
  14. This molecule triggers the production of antibodies in our cell when something foreign has entered our body.
  15. How do antibodies become specific to pathogens? (Include the term epitope)
    • Microbes entering our boddy entering the body is basically a ball of antigens.
    • A WBC responts to this antigen if it has a specific receptor on its surface that binds to that one antigen.
    • The WBC receptor binds to the subunit of the antigen, called the epitope, and each epitope is capable of triggering the production of  unique population of antibodies. 
    • So when a microbe enters the body, many different populations of antibodies can be generated.
  16. For antigens to trigger an immune response, they must be recognized by lymphocytes, prticularly T lymphocytes. Name the role of the 2 types of T-cells
    1. Helper T cell
    2. Cytotoxic T cell
    • Helper T cells: releases cytokines that activate phagocytes and other lymphocytes
    • Cytotoxic T cells: recognize and destroy our body cells that are infected or cancerous.
  17. How do Helper T cells become activated during an immune response?
    • In order to T Helper cells to bind with an antigen, the antigen must be presented to them by an antigen-presenting cell (APC)
    • APC cells include: phagocytes, dendritic cells, or B cells.
  18. What is the importance of the MHC?
    • MHC (major histocompatibility complex) is when T cells only recognize antigen that is displayed within a set of surface proteins.
    • It is essential in the recognition of self vs. Nonself.
  19. The production of antibodies happen in ___.
    B cells
  20. Which has a stronger response: T-dependent antigens or T-independent antigens.
    T-dependent antigens: this results in the development of immunologic memory, whereas T-independent antigens do not.
  21. Explain how antibodies help the immune system (include and define the terms: opsonization, agglutination, neutralization)
    • After B cells are activated and antibodies are produced, the antibodies circulate around the body binding specifically to epitopes of antigens they recognize. 
    • Opsonization is when antibodies enhance phagocytes by helping them recognize antigens easier.
    • Agglutination is the clumping of antigens due to their multiple sites when binding to antigens. It helps prevent the spread of pathogens and makes it easier for phagocytes.
    • Neutralization occurs when antibodies bind to the surfaces of pathogens. Bacteria and viruses both need to bind to host cell receptors, which is prevented by the presence of antibodies on their surface.