Pulmonary Pathology II Flashcards
What is the change in the FEV1/FVC in obstructive airway disease?
FEV1 decreases while FVC is largely unchanged. Thus, the ratio will DECREASE
What is the change in FEV1/FVC in restrictive airway disease?
FEV1 remains normal while the TLC decreases, hence decreasing the FVC. The ratio can be normal or in some cases, increased.
What are some examples of obstructive airway diseases?
- Emphysema
- Chronic bronchitis
- Bronchiectasis
- Asthma
- Tumor
- Foreign body
What are some examples of restrictive airway diseases?
- Due to chest wall disorders (polio, obesity, pleural disease, kyphoscoliosis)
- Interstitial / infiltrative diseases (ARDS, dust diseases, interstitial fibrosis)
Asthma
Intermittent and reversible airway obstruction
- Chronic bronchial inflammation with eosinophils
- Bronchial smooth muscle hypertrophy hyper-reactivity
- Increased mucus production
What is the pathogenesis of atopic asthma?
Immune Mediated. Type I hypersensitivity reaction. Involving Ig E bound to mast cells
• Begins in childhood, triggered by environmental allergens (dust, pollen etc.)
What is the pathogenesis of non-atopic asthma?
Non-immune triggering mechanisms (e.g. respiratory viruses, air pollutants like ozone)
• Hyperirritable bronchial tree; virus induced inflammation of the respiratory mucosa lowers the threshold of subepithelial vagal receptors to irritants
What is the main drug that can induce asthma?
Aspirin
What is occupational asthma?
Asthma develops after repeated exposure to inciding agent - ranges from fumes, to dust to organic agents
What is the cellular mechanism of asthma?
Th2 will produce IL-3/5 which is chemotactic for
eosinophils - IL-4 will lead to the promotion of B cells
to produce IgE
What are some susceptibility genes of asthma?
- ADAM 33- 20q
- Chromosome 5q
Status Asthmaticus
Persistent hyperinflated lungs
What can be seen in asthma mucus under the microscope?
Curschmann Spirals
What can be seen on microscopy of asthma after the degranulation of granulocytes?
Charcot Leyden Crystals
What is the difference between bronchi and bronchioles?
Bronchi have mucus glands and cartilage while bronchioles will have neither
What is the clinical definition of chronic bronchitis?
Persistent productive cough for at least three consecutive months in at least two consecutive years
What are some of the risks for chronic bronchitis?
- Smokers
- Urban dwellers, smog-ridden cities
- Most common in middle aged men
What are the morphological changes with chronic bronchitis?
- Hypertrophy of mucus secreting glands
- Goblet cell metaplasia
- Inflammation
- Fibrosis (bronchiolitis obliterans)
What is the Reid Index?
The Reid index measures the gland to wall ratio (normally glands are 40% of wall thickness as measured from epithelial basement membrane to cartilage) - this will be higher in chronic bronchitis
What are the complications of chronic bronchitis?
Cor pulmonale with cardiac failure
Infections
Bronchogenic carcinoma
How does cor pulmonale result from chronic bronchitis?
Hypoxia of the lung will lead to vasoconstriction in the
lungs which will increase BP - cor pulmonale
How does bronchogenic carcinoma result from chronic bronchitis?
Squamous metaplasia can occur to better handle
the wear and tear - possible leading into cancer from the metaplasia
Emphysema
Destruction of walls of airspaces distal to terminal bronchioles, leading to permanent abnormal
enlargement of air spaces.
What does Centriacinar (Centrilobular) emphysema affect and who does it often affect?
- Upper lobes
- Respiratory bronchioles
- Male smokers
- Often associated with chronic bronchitis
- Coal-workers pneumoconiosis
