medical microbiology

  1. physical barriers
    • skin
    • hair
    • mucous membranes
  2. flushing
    effective in removing microbes out of your body but exposes others to thos microbes
  3. mucociliary escalator
    keeps lungs clea
  4. lysosomes
    (chemical barriers)
    • breakdown peptidoglycan
    • won't work on endospores, mycobacteria, gram negative, and acid fast bacteria
  5. sweat
    (chemical barrier)
    • antimicrobial because it's a a hypertonic solution
    • pH change
  6. defensins in mucosa
    (chemical barriers)
    • like phospholipids (polar and nonpolar region)
    • they can insert directly into the phospholipid bilater and eventually interact with each other
    • works best on gram negative, mycobacterium, enveloped viruses, and protists
  7. iron binding proteins
    (cellular barrier)
    • keep iron from bacteria
    • lactoferin, gerritin, transferris
  8. sebum
    (chemical barrier)
    • oils on our skin
    • tend to be acidic
    • fatty acids also have the ability to inhibit growth
  9. granulocytes involved
    • basophiles: release histamine (dilates capillaries)
    • mast cells: found in tissues: release histamine (associated with allergies)
    • eosinophile: allergy infections and worm infections -- turn of inflamation responce
    • neutrophils: phagocyte -- clean up debris (respond quickly)
  10. agranulocytes involved
    • monocytes: macrophages -- most aggressive in tissue
    • natural killer cells: programmed to recognize cells that aren't healthy
    • lymphocytes
  11. innate defenses
    • act against any type of invading agent
    • perform function before adaptive defnses are activated
    • however the innate actions are necessary to activate the adaptive system`
  12. blood
    • blood flowing out of the wound helps remove microorganisms
    • blood clotting and swelling seals off site
  13. inflammation
    • body's defense responce to tissue damage from microbial infection
    • also responds to cuts and abrasian, burns, sunburn, phenols, acids, alkalis and allergies
    • increase calor, rubor, tumor, and dolar
  14. fever
    • increase in body temperature
    • accompanies inflammation
    • temperature regulated in hypothalamus
    • -raises temperature above optimum temperature for the growth of many pathogens -- slows the rate of growth
    • -higher temperatures makes some microbial enzymes or toxins to become inactive
    • -heightens immune responces by increasing rate of chemical reaction
    • -phagocytosis is enhanced
    • -production of antiviral interferon is icreased
    • -breakdown of lysosomes increased (causing death in infected cells
    • -the patient is more likely to rest
  15. interferons
    • "interfere" with virion replication in other cells
    • breaks down proteins
    • alpha and beta: synthesis occurs only after a virus infects a cell.
    • -synthesized and released to adjacent unaffected cells which then stimulates those cells to produce antiviral proteins within the uninfected cell.
  16. complement
    • regulatory proteins
    • general functions: 1)enhanced phagocytosis by phagocytes 2)lyse microorganisms, bacteria, and enveloped viruses directly 3)generate peptide fragments that regulate inflamation and immune responces
    • begin to work as soon as an invading microbe is detected
    • works as a cascade
    • plasma proteins floating around in an inactivated form
  17. natural killer cells
    • kill certain target cells
    • major histamine complex on surface of cells to let macrophages know they're one of them
    • if the cell doesn't have that they will attack (virus infected cells and cancer cells)
    • always there ready to attack
  18. leukocyte endogenous mediator (LEM)
    • pyrogen
    • decreases iron gut absorption
    • increase iron storage in tissues
    • ---less available to microbes
  19. classical pathway
    begins when antibodies bind to antigen
  20. alternative pathway
    activated by contac between complement proteins and polysaccharides on the pathogen surface
  21. opsonization
    • complement
    • --during phagocytocis some bacteria can prevent phagocytes from adhering to them
    • the complement system counteracts by binding opsonins to the the surface of the infectious agent (allows adherence)
  22. membrane attack complexes
    • complement proteins produce lesions in the cell membrane of microorganisms - causing cellular contents to leak out
    • the complement comlexes combine withint the cell and form a pore consistuting the MAC
    • responsible for direct lysis
    • host plasma membranes contain proteins to protect against MAC lysis
Card Set
medical microbiology
barriers, cells involved, process