introduction to respiratory diseases

Question 1

Asthma and COPD definitions and characteristics

Answer 1

Asthma: reversible increase in airway resistance. Decreases the forced expiratory volume in first second (FEV1)

COPD: chronic bronchitis and emphysema (damaged and enlarged air sacs). Loss of lung function. 80-90% of smoking related deaths from COPD.

Severity of COPD measured by % of predicted normal FEV1.
mild = 80%
moderate = 50-79%
Severe = 30-49%
Very severe = <30%

Question 2

cell lining of the lung

Answer 2

Contain mucous secreting goblet cells (overactivity causes cystic fibrosis) and cilia at the luminal face.

Epithelial cells slightly deeper, with SM below it.

Question 3

Innervation of the airways

Answer 3

B2-ARs found on bronchial smooth muscle. No direct innervation, only circulating adrenaline acts on them. They inhibit mucous gland secretion.

M3 receptors mediate bronchoconstriction and increase mucous secretion

Sensory nerves mediate reflexes, e.g., coughing from irritants. also can increase mucous secretion, and mediate bronchoconstriction. The sensory nerves seem to be unregulated by inflammation - potential role in asthma.

Question 4

B-AR agonists examples and selectivity

Answer 4

Isoprenaline is a nonselective B-AR agonist.

Salbutamol is a B2-AR agonist - also stereoselective - R isomer more potent
Salmeterol is a long lasting B2-AR agonist

Question 5

Asthma pathology

Answer 5

Airway inflammation mediated by mast cells and neutrophils.

Sees increased vascular permeability and thinning of the epithelial layer in the airway.

Mucous build up from overactivation of goblet cells