Respiratory Flashcards
- Define asthma.
Chronic inflammatory airway disorder with recurrent reversible episodes of widespread narrowing of the airways
- List some non-atopic triggers of asthma.
Air pollution
Occupational
Exercise
- Describe the pathogenesis of asthma?
Immediate phase – mast cells degranulate when they come into contact with antigen. Inflammatory mediators are released which causes increased vascular permeability= recruitment of eosinophils and mast cells and bronchospasm
Late phase – tissue damage = increase mucus production and muscle hypertrophy
- List some acute changes seen in asthma.
Bronchospasm
Oedema
Hyperaemia
Inflammation
- List some chronic changes seen in asthma.
Muscular hypertrophy
Airway narrowing
Mucus plugging
- Describe the main histological features of asthma.
Lots of eosinophils and mast cells
Goblet cell hyperplasia
Mucus plugs within airways
Thickening of bronchial smooth muscle and dilatation of blood vessels
- Define chronic bronchitis.
Chronic cough productive of sputum presents for most days for at least 3 months over 2 consecutive years
- List some histological features of chronic bronchitis.
Dilated airways
Mucus gland hyperplasia
Goblet cell hyperplasia
Mild inflammation
- List some complications of chronic bronchitis.
Recurrent infections
Chronic respiratory failure
Pulmonary hypertension and right heart failure (cor pulmonale)
Increased risk of lung cancer (independent of smoking)
- Define bronchiectasis.
Permanent abnormal dilatation of the bronchi with inflammation and fibrosis extending into adjacent parenchyma
- Which part of the lungs tends to be affected most frequently in idiopathic bronchiectasis?
Lower lobe
- List some causes of bronchiectasis.
Infection (MOST COMMON) • Post-infectious (e.g. CF) • Abnormal host defence (e.g. chemotherapy, immunodeficiency) • Ciliary dyskinesia Obstruction Post-inflammatory (aspiration) Interstitial disease (e.g. sarcoidosis) Asthma
- List some complications of bronchiectasis.
Recurrent infections
Haemoptysis
Pulmonary hypertension and right heart failure
Amyloidosis
- Where is the CFTR gene found?
7q3
- What is the most common mutation associated with CF?
Delta F508
- List some clinical manifestations of CF.
GI – meconium ileus, malabsorption Pancreas – pancreatitis Liver – cirrhosis Male reproductive system – infertility Recurrent chest infections
- What is pulmonary oedema?
Accumulation of fluid in the alveolar spaces either due to leaky capillaries or back pressure from a failing left ventricle
This leads to poor gas exchange
- List some causes of pulmonary oedema.
Left heart failure
Alveolar injury (e.g. drugs)
Neurogenic following head trauma
High altitude
- What is diffuse alveolar disease?
Acute damage to alveolar epithelium/endothelium leading to exudative inflammatory rection
- Describe the appearance of the lungs on post-mortem examination in a patient who died from ARDS.
Plum-coloured
Heavy
Airless
- Outline the pathophysiology of ARDS.
Capillary congestion
Exudative phase – the lungs become congested and leaky
Hyaline membranes – form when serum protein that is leaked out of vessels end up lining the alveoli
Organising phase – organisation of the exudates to form granulation tissue sitting within the alveolar spaces
- List some causes of hospital-acquired bacterial pneumonia.
Gram-negatives (Klebsiella, Pseudomonas)
- Which types of bacteria tend to be implicated in aspiration pneumonia?
Mixture of aerobic and anaerobic
- What is bronchopneumonia?
Infection is centred around the airways
Tends to be associated with compromised host defence (mainly the elderly) and is caused by low virulence organisms (e.g. Staphylococcus, Haemophilus, Pneumococcus)
It will show patchy bronchial and peribronchial distribution often involving the lower lobes
- What is lobar pneumonia?
Infection is focused in a lobe of the lung
90-95% caused by S. pneumoniae
Widespread fibrinosuppurative consolidation
- What are the histopathological stages of lobar pneumonia?
Stage 1: congestion (hyperaemia and intra-alveolar fluid)
Stage 2: red hepatisation (hyperaemia, intra-alveolar neutrophils)
Stage 3: grey hepatisation (intra-alveolar connective tissue)
Stage 4: resolution (restoration of normal tissue architecture)
- List some complications of pneumonia.
Abscess formation Pleural effusion Empyema Fibrous scarring Septicaemia
- What is a granuloma?
Collection of macrophages and multi-nucleate giant cells
- Define emphysema.
Permanent loss of alveolar parenchyma distal to the terminal bronchiole due to protease activation
- List some causes of alveolar damage that can lead to emphysema.
Smoking
Alpha-1 antitrypsin deficiency
Rare: cadmium exposure, IVDU, connective tissue disorder
- Describe how the pattern of alveolar damage is different with smoking compared to alpha-1 antitrypsin deficiency.
Smoking – centrilobular damage – loss centred around bronchioles
Alpha-1 antitrypsin deficiency – panacinar (throughout the lungs)
- List some complications of emphysema.
Bullae (can rupture to cause pneumothorax)
Respiratory failure
Pulmonary hypertension and right heart failure
- What is a long term consequence of repeated small pulmonary emboli?
Increase occlusion of pulmonary vascular bed = Pulmonary hypertension
- List some types of non-thrombotic emboli.
Bone marrow Amniotic fluid Trophoblast Tumour Foreign body Air Fat
- What are some causes of pulmonary hypertension?
Pre-capillary Vasoconstrictive - chronic hypoxia Embolic – thromboelmbolism Capillary Widespread pulmonary fibrosis Post capillary Veno-occlusive disease Left sided heart failure
- What are the main types of lung cancer?
Non-small cell carcinoma • Squamous cell carcinoma (30%) • Adenocarcinoma (30%) • Large cell carcinoma (20%) Small cell carcinoma (20%)
- Which types of lung cancer are most strongly associated with smoking?
Squamous cell carcinoma
Small cell carcinoma
- Which type of lung cancer tends to occur in non-smokers?
Adenocarcinoma
- Describe the sequence of histological changes that results in lung cancer.
Metaplasia dysplasia carcinoma in situ invasive carcinoma
- What feature of squamous epithelium makes it vulnerable to undergoing malignant changes?
It does not have cilia leading to a build-up of mucus
Within the mucus carcinogens accumulate
- Where do squamous cell carcinomas and adenocarcinomas tend to arise?
Squamous cell
Centrally – arising from the bronchial epithelium
Adeno - Peripherally – around the terminal airways
- Which mutations are associated with adenocarcinoma in smokers AND non smokers?
SMOKERS
Kras
Issues with DNA methylation
P53
NON SMOKERS
EGFR
- Where does small cell lung cancer tend to arise?
Central – around the bronchi
- What is large cell carcinoma of the lung?
Poorly differentiated tumour composed of large cells
There is no evidence of squamous or glandular differentiation
It has a poor prognosis
- List some common mutations seen in small cell lung cancer.
P53
RB1
- What is the difference in the chemosensitivity of small cell lung cancer and non-small cell lung cancer?
Small cell – sensitive
Non-small cell – not very chemosensitive
- Which molecular changes are important to test for in adenocarcinoma?
EGFR (responder or resistance)
ALK translocation
Ros1 translocation
- What is cancer of the pleura?
Mesothelioma
