Pathology of Lung Disease Flashcards
Asthma
Increased irritability of bronchial tree
Paroxysmal airway narrowing
Reversible - spontaneous or after treatment
Most common asthma
Atopic
triggered by environmental agents
family history
type 1 hypersensitivity reaction
Inflammatory reaction caused by
Mast cells in the bronchi Have IgE on surface Allergen binds to specific IgE antibodies on surface of mast cell and cross links them Cross-linking triggers degranulation Inflammatory mediator release
Treatment of asthma 1) PREVENTATIVE
Brown puff - steroid treatment
reduces number of mast cells in lung
Treatment of asthmas 2) inhibiting degranulation
disodium chromoglycate stabilises mast cell membranes and doesn’t allow it to degranulate
Treatment of asthma 3) after attack
Salbutamol which binds to beta adrenergic receptors and reverses effects of chemical mediators i.e promotes bronchodilation
Chronic obstructive airway disease
2 types
Emphysema
Chronic bronchitis
Chronic bronchitis Characteristics Definiton Aetiology Clinical features
Airways are permanently damaged Cough and sputum for 3 months in 2 consecutive years Air pollution Cigarette smoking Middle aged men Heavy smokers
Chronic bronchitis pathology
microbiology
Defence of ciliated epithelial cells no longer exist More susceptible to infection Mucus hyper secretion Bronchial glands stimulated to produce more secretions Chronic inflammation Squamous metaplasia Dysplasia Bacteria Viruses
Emphysema
anatomical definition
Enlargement of airspaces distal to terminal bronchioles due to destruction of elastin in the walls
Affects efficiency of gas exchange
Lung cancer
Incidence in GB has declined slightly
Greater incidence in increased social deprivation
Lung cancer causes
Smoking
Asbestos exposure
Radon exposure
Lung cancer pathology
Damage of ciliated epithelial cells by damaging agents
Metaplasia from ciliated columnar to squamous
Cells become dysplastic and eventually invasive carcinoma
Lung cancer classification
Small cell and non-small cells
Small cell is highly aggressive
Small cell treated by systemic chemotherapy
Non-small cell is either adenocarcinoma or squamous carcinoma
Economic aspect?
Cigarette tax
Lung cancer treatment is cheap
Ischaemic heart disease
COAD
Prognosis of lung cancer
4-9% overall 5 year survival rate
due to low % of resectable tumours
poor response to systemic chemo
industrial lung disease e.g
pathology
coal worker’s pneumoconiosis
reduction in volume of functional lung tissue
silicosis
cause
pathology
inhalation of small particles of silicates
toxic to macrophages
inflammatory mediators are released into surrounding tissue –> fibrosis
Asbestos
Exposure to asbestos fibre
Asbestos related diseases (4)
Pleural plaque Pleural fibrosis mesothelioma asbestosis lung carcinoma
Mesothelioma
Malignant tumour of pleural surface exposed to asbestos
can appear 40 years after exposures
Lung carcinoma and asbestos
Greater in subjects with asbestos exposure
Increased in cigarette smoking
Cause of lung carcinoma
