D1. Asthma

Question 1

Describe asthma

• what type of response/ what cells are effected
• responsiveness

Answer 1

1. inflam response
   - cells: eosinophils, mast cells and neutrophils
2. Hyperresponsiveness of smooth muscle to contractile stimuli e.g.
   Ach, histamine & PAF
   (3) Hyporesponsiveness of SM to relaxing e.g. adrenaline
   (4) Neuronal imbalance
   (5) Hyperplasia & hypertrophy

Question 2

Describe anatomy of asthma airway

Answer 2

Difficultly breathing: Bronchial smooth muscle cells contract to narrow the airway lumen
Smooth muscle proliferation (hyperplasia) & enlarged cells (hypertrophy) + become ‘synthetic’ (produce inflammatory mediators that can cause contraction of the smooth muscle-bronchoconstriction)
Goblet cells produce excess mucus

Question 3

Structural changes

of asthma

Answer 3

epithelial damage, mucosal oedema, increased intraluminal secretions, basement membrane thickening, smooth muscle hypertrophy and hyperplasia and inflammation

Question 4

Describe proposed models for alteration in smooth muscle excitability (3)

Answer 4

• abnormalities in conduction properties
• alteration in Ca control & contraction/ relaxation
• proliferative response increases

Question 5

Morphology of asthma

Answer 5

• Lungs are over-distended due to over-inflation
• Small areas of atelectasis can be seen
• Occlusion of bronchi and bronchioles by thick tenacious mucous plug:- most striking finding.

Question 6

What is present in the lavage of asthmatics

Answer 6

many eosinophils

(communicates w/ inflammatory cells to amplify the inflammatory response