Pathophysiology of the Respiratory system Flashcards
What are the major genetic causative factors of the respiratory system?
Cystic fibrosis
Asthma
What are the major environmental causative factors in respiratory disease?
Smoking- Lung cancer, Chronic bronchitis (inflammation of the bronchus), emphysema (destruction of alveoli) and susceptibility to infection
Air pollution- Chronic bronchitis and susceptibility to infection
What are the major environmental causative factors in respiratory disease?
Smoking- Lung cancer, Chronic bronchitis (inflammation of the bronchus), emphysema (destruction of alveoli) and susceptibility to infection
Air pollution- Chronic bronchitis and susceptibility to infection
What are the major occupational causative factors in respiratory disease?
Pneumoconiosis (lung disease caused by dust inhalation), asbestosis, mesothelioma (type of lung cancer) and lung cancer
What are the major infectious causative factors in respiratory disease?
Influenza, measles, pneumonia and TB
What is cystic fibrosis (CF)?
> Most common inherited metabolic disease
More common in white people
Abnormal genes carried by approx. 1/20
Affects 1/2000 births
Gene found on chromosome 7 and results in abnormal water and electrolyte transport across cell membranes- makes substances really thick (any substances that sit can cause infection)
What are the 2 ways a foetus can be tested for CF?
Amniocentesis and chronic villus sampling
What is amniocentesis?
> 16 wks+
> When a sample of amniotic fluid is taken and tested
What is chronic villus sampling?
> Newer method
Can be performed much earlier on in pregnancy
Needle into abdomen and a sample of placenta is taken
What is chronic villus sampling?
> Newer method
Can be performed much earlier on in pregnancy
Needle into abdomen and a sample of placenta is taken
What abnormalities may predispose to infection?
1) Loss of cough reflex- coma, anaesthesia, neuromuscular disorders, surgery, stroke
2) Ciliary defects- loss of cilia due to smoking, tumours
3) Mucus disorders- CF, chronic bronchitis
4) Immunosuppression- loss of B/T lymphocytes
5) Macrophage function damage- smoking or hypoxia
6) Pulmonary oedema with flooding of the alveoli (flooding of the lungs with fluid)
What is a primary respiratory infection?
No underlying predisposing conditions in a healthy individual
What is a secondary respiratory infection?
When local/systemic defences are weakened
What is bronchitis?
> Where the bronchial tubes become inflamed and irritated
Characterised by cough, dyspnoea (shortness of breath), tachypnoea and excessive production of sputum
Usually viral but can be bacterial (haemophilus influenzae and streptococcus pneumoniae)
Exacerbations are common in COPD
Affects trachea, larynx and lungs- ‘laryngotracheobronchitis’ or ‘croup’ in infants
More severe in children
Acute bronchitis can be caused by direct chemical injury from air pollutants (smoke, sulphur dioxide and chlorine)
What is pneumonia?
> Alveolar inflammation
Large numbers of lymphocytes and macrophages in the blood
Usually due to infection affecting distal airways, especially alveoli
Causes formation of exudate (fluid)
Streptococcus pneumoniae, streptococcus aureus, mycobacterium tuberculosis, etc