Zusammenfassung der Ressource
CHRONIC INFLAMMATION 1
- An inflammatory response of prolonged duration - weeks,months or indefinite
- Usually PRIMARY but occasionally follows ACUTE
- Provoked by persistence of causative agent
- Characterised with inflammation at the same time attempts healing
- Involved lymphocytes and Macrophages
- FIBROBLASTS are activated laying down new COLLAGEN
- AETIOLOGICAL AGENTS
- RESISTANT INFECTIUOUS AGENTS: organisms that resist host defence
- Tend to avoid phagocytosis and do not produce toxins
- ie mycobacterium tuberculosis
- MICRO-ORGANISMS THAT PERSIST IN DAMAGED REGIONS
- Persist in damaged area where they are protected by pus /abscess cavity
- IRRITANT NON-LIVING FOREIGN OBJECTS
- Cannot be removed by enzymatic breakdown ie wood splinter
- SOME CASES MAY OCCUR IN NORMAL TISSUE
- Disease caused by abnormality in the body's response t its own tissues (auto-immunity)
- UNKNOWN:underlying cause unknown ie Crohns disease
- Intestinal bleeding, ulceration,nausea, fever, abdominal pain
- HOW DOES CHRONIC COME ABOUT?
- DE NOVO: causative agent produces no/or mild acute response
- Progression from acute if original stimuli persists
- Chronic occurs after repeated episodes of acute
- DE NOVO: in most cases there is no phase of acute
- has all histological features of chronic ie no neutrophils
- Transplant rejection involves chronic cell infiltration
- PROGRESSION FROM ACUTE INFLAMMATION:
- Most cases do not progress to acute
- Cases that do are SUPPURATION: abscess or foreign object
- Have the tendency to provoke granulomatous inflammation
- RECURRENT ACUTE EPISODES:
- Usually turn into Chronic
- eg chronic cholecystitis - Gallstones
- starts to replace gall bladder muscle wall into fibrous tissue
- MICROSCOPIC FEATURES:
- Mostly MACROPHAGES, LYMPHOCYTES and PLASMA CELLS
- few EOSINOPHILS and NEUTROPHILS
- Tissue destruction (necrosis)
- EXUDATION OF FLUID is not prominent
- Production of fibrous tissue from granulation tissue
- ACCUMULATION OF MACROPHAGES AND LYMPH OCCUR IN 3 WAYS
- RECRUITMENT FROM CIRCULATION
- LOCAL PROLIFERATION
- PROLONGED SURVIVAL AND IMMOBILISATION OF INFLAMMED AREA
- CELLULAR CO-OPERATION
- B- on contact with antigen form plasma cells (antibodies)
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