TCD 3.3 - Chronic breathlessness

Question 1

What is the location and purpose of the conduction zone and the respiratory zone?

Answer 1

Conduction (Trachea-Terminal bronchioles) = Air warmed and humidified. Ciliated cells remove particles

Respiratory (Respiratory bronchioles-Alveoli) = Gas transfer

Question 2

What happens in a sympathetic response on bronchiolar smooth muscle? (neurotransmitter, receptor, result)

Answer 2

Noradrenaline
Beta receptors
Bronchodilation

Question 3

What happens in a parasympathetic response on bronchiolar smooth muscle? (neurotransmitter, receptor, result)

Answer 3

Acetylcholine
Muscarinic receptors
Bronchoconstriction

Question 4

What are type 1 alveolar cells? (function, appearance, abundance)

Answer 4

Gas exchange
Large squamous
Less numerous

Question 5

What are type 2 alveolar cells? (function, appearance, abundance)

Answer 5

Secrete surfactant from secretory organelles
Smaller cuboid
More numerous

Question 6

What is the MRC Dyspnoea scale?

Answer 6

1-Not troubled by breathlessness except on strenuous exercise

2-Short of breath when hurrying or walking up a slight hill

3-Walks slower than contemporaries on level ground because of breathlessness, or has to stop for breath when walking at own pace

4-Stops for breath after walking about 100 metres or after a few minutes on level ground

5-Too breathless to leave the house, or breathless when dressing or undressing

Question 7

What sort of differential questions could you ask for breathlessness?

Answer 7

Variation at different times of day
Night time symptoms
Symptoms when lying flat
Ankle swelling
Chest pain
Light-headedness
Occupational history
Asbestos exposure
Pets
Birds
Smoking