Respiratory Pathology Flashcards
what is bronchitis
secondary bacterial infection of the bronchi
how does bronchitis present
chronic inflammation of bronchi, excess mucous production, chronic productive cough
what causes bronchitis
smoking, prolonged exposure to harmful particles and gases, genes, age
effects of bronchitis on the body
- increased size and number of mucus glands- may block small airways and overwhelm ciliary escalator
- oedema and other inflammatory changes- swelling and thickening of airway wall narrows the lumen and obstructs airflow
- reduction in number and function of ciliated cells- ciliated epithelium progressively destroyed and replaced by non-ciliated epithelium
- fibrosis of the airways- inflammatory changes lead to fibrosis and stiffening of airway walls, further reducing airflow
- breathlessness- ventilation of the lungs becomes severely impaired
what is asthma
a common inflammatory disease of the airways, associated with episodes of reversible hyperreactivity of the airway smooth muscle
how does asthma present
difficulty breathing, wheezing, reduced peak flow
what causes asthma
childhood-onset asthma- allergens inhaled
adult-onset asthma- female sex, smoking, pre-existing respiratory conditions, obesity
effects of asthma on the body
mucus membrane and muscle layers of the bronchi and bronchioles become inflamed and swollen, reducing airflow into the lower respiratory tract. only partial expiration is achieved so the lungs become hyperinflated which causes the symptoms
what is tuberculosis
bacterial infectious disease that affects the respiratory system
types of TB
pulmonary TB- primary and secondary TB
non-pulmonary TB- miliary, lymph node, joint and bone
how does pulmonary TB present
primary- very few symptoms
secondary- fever, cough, malaise, haemoptysis, weight loss, night sweats
what causes pulmonary TB
caused by bacteria- mycobacterium tuberculosis and mycobacterium bovis (from cows). spread by inhalation.
effects of pulmonary TB on the body
initial infection- TB bacteria taken up by macrophages but protected from phagocytosis by their thick cell wall. inflammatory cells seal off these infected lesions in Ghon foci. the centre of these Ghon foci contain necrotic material
reactivation can cause the infection to progress
what is respiratory failure
a condition in which the respiratory system fails in one or both of its gas exchange functions due to dysfunction of one or more essential components of the respiratory system
types of respiratory failure
type 1- hypoxaemic
type 2- hypercapnic
type 1 resp failure causes
cardiogenic pulmonary oedema, pneumonia, pulmonary embolism
type 2 resp failure causes
severe asthma, chronic bronchitis and emphysema, drug overdose, chest wall abnormalities, MG
type 1 resp failure effects on body
V/Q mismatch- volume of air flowing in and out of lungs does not match flow of blood to lung tissue
causes PaO2 to fall and PaCO2 to rise
rise triggers increase in ventilation which corrects PaCO2 but not PaO2
PaO2 less than 8kPa
effects of type 2 resp failure on body
alveolar hyperventilation prevents adequate oxygenation and pt eliminating CO2 from blood
PaO2 decreases and PaCO2 rises
PaCO2 more than 6.7kPa
