22. when things go wrong Flashcards
types of respiratory disease (3)
obstruction
restriction
infection and inflammation
obstructive respiratory disease
impede the rate of flow into and out of the lungs
increased airway resistance=narrowing of airways
decreased outflow pressure=elastic recoil of lungs lost
restrictive respiratory disease
condition which cause reduced lung volume
reduced compliance means a decrease in the vital capacity
an increase in airway resistance and a decrease in the outflow pressure lead to
a decreased forced expiratory volume FEV and an increase in residual volume RV
(looks like chest is overinflated)
chronic obstructive pulmonary diseases
chronic bronchitis = narrowing of airways
emphysema= elastic recoil of lings lost
what is chronic bronchitis
inflammation of the bronchi irritants cause inflammation in bronchi abnormal mucus secretion plugs airways prone to infection leads to further inflammation
two types of bronchitis
acute due to bacteria/virus
chronic due to smoking or environmental irritants
symptoms of chronic bronchitis
airway obstruction
shortness of breath/wheezing
chest pain
chronic (productive) cough
treatment of bronchitis
stop smoking
bronchodilators
antibiotics
mechanism of emphysema
smoking triggers the release of neutrophils and macrophages which release elastase
elastase is normally inactivated by a1 antitrypsin but some COPD patients have a genetic deficiency of a1 antitrypsin
elastase is therefore not inactivated and goes on to destroy alveolar walls (emphysema)
why does emphysema lead to a chronically over inflated lung
the compliance is significantly above normal
leading to increased residual volume which leads to an increased forced forced residual capacity
symptoms of emphysema
shortness of breath on exertion
hyperventilation
expanded chest
lifelong smokers
loss of alveoli is permanent and irreversible
give enzyme supplements in a1 antitrypsin deficiency
lung transplant, supplemental O2
symptoms of asthma
bronchoconstriction
oedema of airway mucosa
mucus secretion
-all lead to increased airway resistance
causes of asthma
hypersensitivity reaction to allergens air pollution exercise and cold air emotional stress genetics ?
mechanism of asthma
mast cell activation
leading to histamine and cytokine release
leading to oedema, mucus, smooth muscle contraction
treatment of asthma
bronchodilators eg salbutamol
anti-inflammatories
2 main disorders of restrictive lung disease
fibrosis- the development of excessive connective tissue, makes lungs stiffer
respiratory distress syndrome (IRDS, ARDS, SARS)
restrictive lung disease symptom
alveolar walls become rigid
mechanism for acute restrictive lung disease
sepsis or sever trauma
protein exudation
oedema
mechanism for chronic restrictive lung disease
industrial dust, drugs, rheumatism leads to inflammation which leads to fibrosis
honeycomb lung
alveoli are replaced by fibrotic tissue leading to decreased lung compliance
causes of honeycomb lung
inhaled environmental and occupational pollutants
cigarette smoke
autoimmune disease
which are more common, upper respiratory tract infections or lower respiratory tract infections
upper
