Introduction |
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Introduction:
The endogenous and exogenous stimuli that cause cell injury
and necrosis can incite a complex reaction within vascularized connective
tissues called inflammation. Inflammation is essentially a protective
response designed to dilute and then eliminate or isolate both the initial
cause (eg microorganisms, toxins or ionising radiation) and the necrotic
cells arising as a consequence of such injury.
Inflammation involves both tissue injury (often as a side
effect of bactericidal and degradation activities) and the subsequent
processes of healing by either regeneration or fibrosis (or both).
Inflammation is characterised broadly into acute and chronic, although
acute inflammatory reactions will give way to chronic inflammation if
the inciting cause persists for more than 2 days.
Acute inflammation lasts for minutes to a few days and is characterised
by vasodilation and increased vascular permeability, leading to a protein
rich fluid exudate and neutrophil infiltration into the inflammatory site.
Chronic inflammation lasts for days to years and is characterised by
macrophages and to a lesser extent lymphocytes, as well as fibrosis and
angiogenesis.
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