Difference between revisions of "Lungs Inflammatory - Pathology"
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[[Image:Acute exudative pneumonia.jpg|right|thumb|150px|<small><center>Acute exudative pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]] | [[Image:Acute exudative pneumonia.jpg|right|thumb|150px|<small><center>Acute exudative pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]] | ||
[[Image:Acute exudative pneumonia - gross.jpg|right|thumb|150px|<small><center>Acute exudative pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]] | [[Image:Acute exudative pneumonia - gross.jpg|right|thumb|150px|<small><center>Acute exudative pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]] | ||
+ | [[Image:Acute necrotising pneumonia.jpg|right|thumb|150px|<small><center>Acute necrotising pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]] | ||
*Regardless of the pattern, all pneumonias pass through three stages: | *Regardless of the pattern, all pneumonias pass through three stages: | ||
**'''Exudative phase''' | **'''Exudative phase''' | ||
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=='''Other forms of pneumonia'''== | =='''Other forms of pneumonia'''== | ||
− | |||
===[[Aspiration Pneumonia]]=== | ===[[Aspiration Pneumonia]]=== |
Revision as of 18:23, 19 February 2011
Pneumonia - Introduction and Classification
- Pneumonia
- Inflammation that takes place in the alveoli and their walls
- Can be grouped either according to
- Nature of the inflammatory process
- Aetiological agent
- Pattern of the lesion
- Patterns of lung inflammation vary depending on the aetiology, route and method of exposure and multiple host factors including age, general health, and immune status
- There are five general patterns of pneumonia:
Bronchopneumonia
Bronchointerstitial Pneumonia
Lobar Pneumonia
Interstitial Pneumonia
Embolic Pneumonia
Granulomatous Pneumonia
Verminous Pneumonia
Stages of pneumonia
- Regardless of the pattern, all pneumonias pass through three stages:
- Exudative phase
- In this initial stage inflammatory exudate pours into alveolar spaces and alveolar capillaries are congested
- Type I alveolar epithelial cells are highly sensitive to injury and cannot proliferate in response to injury
- Necrosis and sloughing of injured type I cells, denuding alveolar spaces of lining epithelium
- Neutrophils begin to enter alveolar spaces distended with inflammatory oedema
- Proliferative phase
- Type II alveolar cells (less sensitive to and can proliferate in response to injury) begin to proliferate within 24 hours and eventually line the alveolar walls denuded of type I cells ***By 6 days cuboidal type II cells can completely line the alveoli
- Proliferation of type II cells marks the shift from the exudative to the proliferative stage of pneumonia, also heralded by decreased blood flow in alveolar capillaries
- Because the original squamous type I cells have been replaced by cuboidal type II cells, the microscopic appearance of pneumonic lungs at about 1 week has been described as “alveolar epithelialization”, “alveolar adenomatosis”, or “bronchiolisation of alveoli”
- Repair phase
- Resolution of pneumonia is accomplished by transformation of type II cells to type I cells
- Exudative phase
Pulmonary abscesses
Infectious causes of pneumonia