15. Obstructive and Restrictive lung disease Flashcards
What is meant by obstructive disease?
Increase in resistance to airflow due to partial or complete obstruction of airways
What is meant by restrictive disease?
Reduced expansion of lung parenchyma
Reduced total lung capacity
What is the spirometry test?
A test can help diagnose various lung conditions
What does the spirometer measure?
The amount and/or speed of air that can be inhaled and exhaled
What is FEV1?
Forced expiratory volume in one second
The amount of air you can blow out within one second
Normal lungs and airways can normally blow out most of the air from your lungs within one second
What is FVC?
Forced vital capacity
The total amount of air that you blow out in one breathe
What does an obstructive pattern look like on spirometry?
FEV1 is reduced and the ratio of FEV1/FVC is lower than normal
Airway is narrowed so the amount of air can be blown out quickly is reduced
FVC is also reduced
What does a restrictive pattern look like on spirometry?
FVC is less than the predicted value for your age, sex and size
FEV1 is also reduced
Ratio of FEV1/FVC is normal
What are the clinical features of asthma?
A chronic disease characterised by recurrent attacks of breathlessness and wheezing
What are the pathological features of asthma?
Reversible small airways obstruction characterised by bronchospasm, inflammation and oedema: paroxysmal
What are causes of asthma?
Heat
Cold
Exogenous allergens
Chemicals eg. aspirin
Describe the pathogenesis of asthma
Hypertrophy of peribronchial muscle
Increased mucus production by goblet cells
Eosinophils, Mast cells, Type II Helper T cells, neutrophils
What does hypertrophy of the smooth muscle cause?
Narrowing of the airways
Increased reactivity to allergens, infecctions, irritants, parasympathetic stimulation
Triggering of bronchostriction
What does COPD stand for?
Chronic Obstructive Pulmonary Disease
What is COPD?
A lung disease characterised by chronic obstruction of lung airflow that interferes with normal breathing and is not fully reversible
What is are the reasons for shortness of breathe?
Due to difficulty exhaling all the air from the lungs
How is cigarette smoking a major cause of emphysema?
Activation of inflammatory pathways
Digestion of lung parenchyma by leukocyte metalloproteinases and elastases
Oxidants from cigarette smoke and inflammatory cells
IL-8 secretion recruits neutrophils that are primed by TNFalpha and cause damage to extracellular matrix
What is alpha-1 antitrypsin deficiency?
Genetic abnormality of a protease inhibitor
If proteases are uninhibited - lead to the loss of lung tissue and to emphysema
Define chronic bronchitis
A cough productive of sputum on most days for 3 months of the year for at least 2 successive years
What are the histological changes in chronic bronchitis?
Chronic inflammatory cells infilatrate in walls of bronchi and bronchioles
Bronchial mucous gland hypertrophy
What are restrictive disease caused by?
Caused by disease in the interstitium of the lung
What do restrictive lung diseases involve?
An increase in the amount of fibrous tissue in the alveolar walls of the lungs
The lung will be stiff with reduced compliance
What are examples of some conditions of restrictive lung disease?
Interstitial ling disease Sarcoidosis Obesity Scoliosis Neuromuscular disease
What is asbestosis?
Interstitial fibrosis of lung die to asbestos exposure
