Difference between revisions of "Chronic Inflammation - Introduction"
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m (Text replace - "[[Lymphocytes|" to "[[Lymphocytes - Introduction|") |
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==Cells== | ==Cells== | ||
− | * The principal inflammatory cells involved are [[Lymphocytes | + | * The principal inflammatory cells involved are [[Lymphocytes|lymphocytes]] and [[Macrophages|macrophages]]. |
** Fibroblasts and vascular endothelium also have important roles. | ** Fibroblasts and vascular endothelium also have important roles. | ||
===Accumulation of Macrophages=== | ===Accumulation of Macrophages=== |
Revision as of 12:16, 4 August 2010
Introduction
- Chronic inflammation may:
- Follow on from an unresolved acute inflammation.
- Be chronic from the beginning.
- Is usually of slow onset and long duration, and very insidious in nature.
- There is a slow progressive destruction of the original tissue.
- Chronic inflammation is characterised by cellular infiltration and proliferation of local connective tissue.
- Often found around focal areas of necrosis.
Cells
- The principal inflammatory cells involved are lymphocytes and macrophages.
- Fibroblasts and vascular endothelium also have important roles.
Accumulation of Macrophages
- Under certain circumstances, macrophages accumulate.
- Impaired digestive ability of the macrophages to cope with foreign material.
- E.g. thorns, sutures, grit etc.
- The irritant being able to coat itself with host antigens.
- E.g. Actinobacillus bacteria form enveloping 'clubs'.
- The irritant's own coating being impervious to digestion by the macrophage.
- E.g. tubercle bacillus and fungi.
- Impaired digestive ability of the macrophages to cope with foreign material.
Fibroblasts
- Derived from local connective tissue cells.
- Involved in the organisation of damaged tissue.
- Replacement repair.
Endothelium
- As well as fibroplasia (organisation) and macrophages mopping up debris, the vascular endothelium proliferates into the organising tissue.
- Endothelium is a prominent component of the 'pyogenic membrane’ in abscess formation.
- The vessels bring neutrophils into the centre of the abscess.