Home / Summaries / Cases for Clinical exercise physiology / lung-lungs-fev1-0

Alveolar oxygen transport

4 important questions on Alveolar oxygen transport

What are dynamic lung volumes?

Dynamic lung volumes are lung volumes that depend upon the rate at which air flows out of the lungs. These include:
- Forced expiratory volume: usually measured over 1 second: FEV1.0.
- Tiffenau-measurement: FEV1.0/VC, this normally approximately is 85%
Dynamic ventilation depends on two factors:
- Maximum stroke volume of the lungs (FVC) and
- Speed of moving a volume of air. This depends on the resistance of the respiratory passages to the smooth flow of air and the lung compliance.

What is restrictive/obstructive?

Obstructive lung diseases: a form of lung disease that manifests as acute or chronic, narrowing or blockage of the smaller airways in the lungs, causing increased resistance to airflow in the bronchial tubes (for example chronic bronchitis, emphysema (last two together are referred as COPD), and asthma)
Restrictive lung diseases: pulmonary disease with abnormal reduction in pulmonary ventilation, along with diminish lung expansion. They have got stiffer lungs. E.g. pulmonary fibrosis or interstitial lung disease.

Which alterations of static and dynamic lung volumes do you expect at the disorders summarized in the previous question?

In obstructive lung disease the FEV1.0/VC reduces. The demarcation point for airway obstruction is an FEV1.0/VC of 70%.
In restrictive lung diseases all the statistic lung volumes decrease, the FEV1.0 and the VC decrease in the same proportion. So the Tiffenau-measurement stays the same.

What are the reserves of the pulmonary system in healthy people at rest: diffusion capacity and respiratory pump?

Diffusional reserve is determined by T/. As long as <T full diffusional equilibrium is reached: Pa=PA. Gas exchange is perfusion limited. A subject has a diffusional reserve in his lungs of 5 MET.

The question on the page originate from the summary of the following study material:

Cases for Clinical exercise physiology

View summary