Obstructive and Restrictive Lung Disease

by Greg Crowther

Fundamentally, limitations in the movement of air into and out of the lungs can be due to a restrictive problem, in which the lungs are not able to inflate to their normal extent, and/or an obstructive problem, in which the airways (not the lungs themselves) offer higher-than-normal resistance to airflow. The basic distinction can be understood in terms of clinical measurements of FVC and the FEV₁/FVC ratio.

CHORUS:
Lung spirometry: so important clinically.
Quantify the flow through the pulmonary tree.
Lung spirometry: inhale, exhale forcefully.
Quantify the flow through the pulmonary tree.

When the main thing that you know
Is that FVCs are low,
Restrictive lung disease might be the thing that limits flow.
If FEV₁/FVCs
Are ratios too small to please,
You should look for other symptoms of obstructive lung disease.

CHORUS

• sheet music (with melody play-back)

Songs like this one can be used during class meetings and/or in homework assignments. Either way, the song will be most impactful if students DO something with it, as opposed to just listening.

An initial, simple follow-up activity could be to answer the study questions below. A more extensive interaction with the song might entail (A) learning to sing it, using an audio file and/or sheet music as a guide, and/or (B) illustrating it with pictures, bodily poses, and/or bodily movements. The latter activity could begin with students identifying the most important or most challenging content of the song, and deciding how to illustrate that particular content.

(1) What is the FVC?

(2) What is the FEV₁?

(3) Why might people with restrictive lung disease have abnormally low FEV₁'s? How can these people be distinguished from people with obstructive disease, which also results in low FEV₁'s?

(4) In what sense is the respiratory system a "pulmonary tree"?