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glossary:inflammatory_response

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glossary:inflammatory_response [2007/09/08 09:56]
Pat O'Connor created
glossary:inflammatory_response [2012/10/16 14:40] (current)
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 +The process works alongside non-specific cellular response. The two act quickly upon [[infection]].
 +It is also beneficial to the action of specific [[immune system]]s.
 +
 +Comes about as a result of chemical messages produced by "​mediators"​.
 +
 +There are two major groups of mediators.
 +
 +Cell Derived Mediators (produced by White Blood Cells)
 +
 +[[Plasma]] Derived Mediators (found in the blood plasma)
 +
 +1. Cell Derived Mediators
 +
 +Arachidonic acid derivatives (Prostaglandins and Leukotrines)
 +Also involved in blood clotting.
 +Produced rapidly local to the site of infection.
 +Short range of action.
 +Degenerate spontaneously.
 +
 +N.B. Corticosteroids and Aspirin reduce [[inflammation]] by inhibiting the production of prostaglandins.
 +
 +Cytokines Lymphokines and Monokines
 +
 +One of the most important of these is a substance known as interleukin.
 +This stimulates [[lymphocytes]] and other [[white blood cells]] into action.
 +Also promotes fever by resetting the body's thermostat located in the hypothalamus. In addition it induces drowsiness (somnolence).
 +
 +Platelet Activating Factor (PAF)
 +Produces vasodilation.
 +Makes [[blood]] and [[lymph vessel]]s more permeable.
 +Stimulates production of prostaglandins.
 +
 +Histamine
 +
 +Effects are vasodilation and increased vascular permeability. Appears to be effective in the early stages as evidenced by the fact that antihistamines have no effect upon vascular permeability 1 hour after the onset of [[inflammation]].
 +
 +Kinin System
 +
 +Major active component is bradykinin.
 +An extremely potent vasodilator,​ one of the most powerful known.
 +Also induces [[pain]] at the site of [[infection]].
 +
 +Plasma Derived Mediators
 +
 +Complement
 +
 +An extremely important complex of over 20 proteins found in the blood plasma
 +Increases vascular permeability.
 +Opsonisation basically coating invading cells in order to make them more appetisin to phagocyic cells.
 +Chemotaxis producing chemicals which attract important elements of the specific and non-specific defence mechanisms to the site of infection.
 +Direct lysis of organisms.
 +
 +Interferons
 +
 +These are chemical messages from virally infected cells that are borne in the plasma.
 +They stimulate other cells to produce anti-viral [[protein]]s.
 +Virus particles produced in cells exposed to interferon are less effective at infecting other cells.
 +Also stimulate Natural Killer Cells into action.
 +N.B. They are not viral specific and cannot save the infected cell. Appear to be most effective in short term viral infections such as colds and flu.
 +
 +Overall effects of the inflammatory response
 +
 +[[Blood vessels]] in the infected area dilate, and as a result blood flow to the area increases.
 +This makes skin in the area look red and feel warm.
 +[[Capillaries]] in the area become more permeable allowing fluid to seep into the surrounding tissue.
 +As this occurs oedematous swelling around the infected site occurs.
 +The swelling and the effects of some of the chemicals released results in pain.
 +Hence clinical characteristics of the inflammatory response are known as redness, heat, oedema and pain.
 +
  
glossary/inflammatory_response.txt ยท Last modified: 2012/10/16 14:40 (external edit)