Pathology of COPD Flashcards
What are the three disease that are classed as COPD?
Chronic bronchitis
Emphysema
Small airway disease
What are the symptoms of chronic bronchitis?
Cough productive of purulent suptum for:
>= 3 months of the years
>= 2 successive years
What other chronic conditions associated with a wheeze may have similar symptoms to chronic bronchitis?
Asthma
Bronchiectasis
What is the definition of chronic bronchitis?
An inflammatory process in the wall of the bronchioles with excessive production of mucus and sputum for hypertrophic glands
Small airways are narrow, and a morning cough more than 3 months per year
What are the causes of chronic bronchitis?
Cigarette smoke and other similar irritants
How does cigarette smoke irritate the epithelial cells?
Cause an inflammatory cell infiltration
- neutrophils
- CD8 +ve lymphocytes
Cause an increase in:
- Goblet cells
- Mucous glands
- Mucus in airway lumen
Describe the histopathology of chronic bronchitis
Increased inflammatory cells in the submucosa
Note: submucosal neutrophils and macrophages release proteases
How can patients have/develop emphysema?
Due to an alpha-1 antitrypsin deficiency
- alpha-1-antitrypsin inhibits alpha-1-protease
Release of proteases by inflammatory cells due to having chronic bronchitis
- overwhelms body anti-proteases => destruction of alveolar walls
What does the connective tissue in the normal alveolar wall consist of?
Elastin
Collagen
What is emphysema?
Destruction of lung tissue distal to terminal bronchioles
- causing floppy and dilated airways
- collapse on expiration due to a loss of support
note:
- degenerative loss of radial traction of bronchial walls
- loss of elastin in alveolar walls
What is small airway disease?
Thickening and fibrosing of terminal bronchioles
- unlike emphysema
Progression of COPD correlates with:
- wall volume
- inflam. cells
- mucous in lumen
What are the physiological consequences of emphysema?
Airflow obstruction
Gas trapping
Hyperinflated chest (Barrel chest)
Loss of capillary bed
Reduced blood flow though lungs
Pulm. hypertension => cor pulmonale (enlarged R. heart)
What does alpha-1 anti trypsin do?
Ihibits alpha-1-protease
What is the effect of having increased proteases on the body?
Overwhelms body anti-proteases
=> destruction of alveolar walls
What is the purpose of elastin in the connective tissue of the alveolar wall?
Sheets surround alveoli
Stretch and elastic recoil
