Week 5 RESPIRATORY PATHOLOGY Flashcards
What is the histology of the conducting airways?
Pseudostratified cilliated columnar mucus secreting epithelium
What is the histology of the alveoli?
Mostly flat Type I pneumocytes (gas exchange) & some rounded Type II pneumocytes (surfactant production)
What is the partial pressure of oxygen during respiratory failure?
PaO2
What is the cause of respiratory failure?
Due to defective:
Ventilation
Perfusion
Gas exchange
What is Type I respiratory failure?
Type I (paCO2
What is Type 2 respiratory failure?
(paCO2>6.3kPa)
Hypercapnic respiratory drive
What are the general Respiratory signs & symptoms?
What does each one indicate?
There is 9
Sputum - Mucoid, purulent, haemoptysis
Cough - Reflex response to irritation
Stridor - Proximal airway obstruction
Wheeze - Distal airway obstruction
Pleuritic pain - Pleural irritation
Dyspnoea - Impaired alveolar gas exchange
Cyanosis - Decreased oxygenation of haemoglobin
Clubbing -
Weight loss - Catabolic state with chronic inflammation or tumours
What do the different auscultation of respiratory examination indicate?
Crackles – Resisted opening of small airways
Wheeze – narrowed small airways
Bronchial breathing – Sound conduction through solid lung
Pleural rub – Relative movement of inflamed visceral & parietal pleura
What do the different percussion of respiratory examination indicate?
Dull – Lung consolidation or pleural effusion
Hyperesonant – Pneumothorax or emphysema
How common are primary benign lung tumours?
Give a example
Rare
Example is adenochondroma
What percentage of primary lung cancer is carcinoma based?
90%
What is the biggest risk factor of lung carcinoma?
cigarettes (80%)
Secondary cigarette smoke - 10-30% increase
What are the risk factors of lung carcinoma?
asbestos, high level exposure, with or without asbestosis
lung fibrosis – including asbestosis and silicosis
radon
chromates, nickel, tar, hematite, arsenic, mustard gas
What does high doses of asbestoscause?
High level exposure produces pulmobary interstitial fibrosis –>asbestosis
What does asbestos look like under a ligh microscope?
Fibres coated with mucopolysacharide & ferric iron salts
What is the most dangerous type of asbestos?
Crocidolite –> blue asbestos
What is the least dangerous type of asbestos?
White asbestos (chrysotile)-
What is Mesothelioma?
A cancer of mesothelial tissue, associated especially with exposure to asbestos
What is high levels of asbestos linked to?
Higher incidence of all types of lung carcinoma
what is the problem in linking asbestos to lung carcinoma?
Effects of smoking – multiplicative risk
Diagnosing asbestosis
Quantification of asbestos exposure
What are the two types of lung carcinoma?
non-small cell carcinoma (85%)
small cell carcinoma (15%)
Give examples of non-small carcinoma?
squamous carcinoma 52%
adenocarcinoma 13%
large cell neuroendocrine carcinoma
undifferentiated large cell carcinoma
What type of cells are small cell carcinoma?
All are neuroendocrine
What are neuroendocrine cells?
Neuroendocrine cells are cells that receive neuronal input and, as a consequence of this input, release hormones to the blood.