micro exam 3 part 3

  1. What causes the skin to be a not favorable place for bacteria growth?
    Slightly acidic pH, a high concentration of sodium chloride, and lack of moisture in many areas. The outer layer of the skin has a thick layer of closely packed cells called keratinocytes, that helps prevent against penetration of bacteria and continuous shedding of the outer epithelial cells prevents build up of microorganism.
  2. What are the most numerous bacteria of skin glands?
    Propionibacterium acnes.
  3. How are the lungs protected from microorganisms?
    • 1. A continuous stream of mucus is generated by the goblet cells and traps microorganisms. The ciliated epithelial cells constantly move the trapped microorganisms out of the respiratory tract
    • 2. Alveolar macrophages destroy (phagocytize) pathogens that get to the alveoli.A bactericidal effect is then exerted by lysozyme (an enzyme that is present in the nasal mucus)
  4. What is the role of complement in the immunity process?
    Complement is a heat-liable component of human blood plasma that augments phagocytosis. It is composed of over 30 serum proteins . It defends against bacterial infections, bridges innate and adaptive immunity, and disposes of waste. It works in a cascade fashion (once one is activated it triggers the activation of others).
  5. Characteristics of gnotobiotic colonies or organisms.
    Animals or organisms that are germfree or one that which all microbiota are known. They are usually more susceptible to pathogens, thus, the number of microorganisms necessary to infect and produce disease are much smaller.
  6. What is the role of complement in the immunity process?
    Complement is a heat-liable component of human blood plasma that augments phagocytosis. It is composed of over 30 serum proteins . It defends against bacterial infections, bridges innate and adaptive immunity, and disposes of waste. It works in a cascade fashion (once one is activated it triggers the activation of others).
  7. What do natural killer cells kill?
    Malignant cells, and cells infected with microorganisms.
  8. What is the most prevalent bacterium found in the colon?
    Duodenum?
    • 1. Anaerobic, gram-negative and positive bacteria, spore-forming and nonsporing rods
    • 2. Duodenum? Gram-positive cocci and rods.
  9. Where is the largest microbial population found?
    Large intestine (Colon)
  10. The external ear flora resembles what other type of flora?
    Skin
  11. What are the main organisms found in adult pre-menopausal female reproductive tract?
    Lactobacillus acidophilus.
  12. Why do females have more UTI’s then males?
    Because the female has a much shorter urethra than a male, so it is much easily traversed by microorganisms
  13. Which complement pathway is important in innate immunity, but not effective of bacteria and fungi invasion?
    Alternative complement pathways.
  14. How does fever augment the host’s defenses?
    How is fever response triggered?
    • A. Fever works by one of 3 complementary pathways
    • 1. It stimulates leukocytes to destroy microorganisms.
    • 2. Enhances specific activity of the immune system.
    • 3. and enhances microbiostatsis (growth inhibition) by decreasing available iron to the microorganism.
    • B. Endogenous pyrogen is released by macrophages during infection.
  15. What happens to the immune system with aging?
    Autoimmune disease- activation of T & B cells, that lead to tissue damage.
  16. Where are lymph nodes located?
    What do they do?
    • 1. Throughout the body in the junction of the lymphatic vessels.
    • 2. Filter and remove foreign antigens, and the activation andproliferation of lymphocytes.
  17. How does super antigens exert their damage?
    Trick T-cells into activation with no specific triggering agent, causing massive quantities of cytokines CD4+T-cells, leading to organ failure and suppression of specific immune responses.
  18. What causes a granuloma to form?
    When Neutrophils and macrophages are unable to destroy the microorganism during inflammation, it starts to wall off and isolate the site causing granuloma.
  19. How are mictobiota of the skin checked?
    The skin provides a mechanical barrier to microbial invasions, due to its thick closely packed cells; frequent shedding, and being acidic and salty.
  20. How does humoral immune response differ from cell-mediated immune response?
    Humoral immunity action antibodies by tagging and marking bacteria, toxins and viruses for destruction. Cell-mediated immunity T-cells directly attack infected cells.
Author
sapperwife
ID
93314
Card Set
micro exam 3 part 3
Description
micro exam 3 part 3
Updated