Chronic Inflamation Flashcards
Explain the sequelae of acute inflammation?
diagram
What factors favour resolution?
- minimal cell death and tissue damage
- occurrence in an organ/tissue with regenerative capacity (eg. liver)
- rapid destruction of the casual agent
- rapid removal of fluid and debris by good local vascular drainage
What is resolution?
- active process aimed at restoration of tissue and function
- it involves apoptosis and subsequent clearance of activated inflammatory cells
What is a casual agent?
biological pathogen that causes disease
What happens is resolution cannot occur?
organisation
What is organisation?
replacement of destroyed tissue by granulation tissue
What is granulation tissue?
new connective tissue and microscopic blood vessels that form on the surfaces of wounds during the healing process
- light red/pink colour, soft, moist, pulseful, bumpy, painless when healthy
How is granulation tissue formed?
Inflammatory exudate replaced by: - capillaries - macrophages - fibroblasts - collagen Regulated by growth factors: -TNF - EGF - FGF
What factors favour organisation?
- large amounts of fibrin
- substancial necrosis
- exudate and debris cannot be removed or discharged
What causes chronic inflammation?
- primary causes - does not have an acute response (eg. arthritis)
- progression from acute inflammation
- recurrent episodes of acute inflammation
What are the factors favouring progression from acute to chronic inflammation?
- indigestible substances eg. glass, suture material - foreign body reaction
- deep seated suppurative inflammation where drainage is delayed or inadequate - (thick abscess wall - fibrous/granulation tissue - pus becomes organised - forms fibrous scar) - deep seated bone abscesses
- recurrent episodes of acute inflammation and healing may eventually result in chronic inflamation - macrophages and lymphocytes used instead of neutrophils
What is osteomyelitis
chronic bone abscess which is difficult to treat
What are the primary cells of chronic inflammation?
macrophages
lymphocytes
plasma cells (activated by lymphocyte)
What are the primary cells of acute inflammation?
neutrophils
What does chronic inflammation look like?
- chronic ulcer (mucosa breached, base lined by granulation tissue, fibrous tissue throughout muscle layers)
- chronic abscess cavity
- thickening of the wall of a hollow viscus
- granulomatous inflamation (TB)
- fibrosis