Question

What does FEV1/FVC measure, and why will the ratio increase with lung fibrosis?

a) Measures lung capacity, and the ratio increases due to increased lung compliance.
b) Measures the forced expiratory volume in one second relative to forced vital capacity, and the ratio increases due to decreased lung compliance.
c) Measures oxygen saturation, and the ratio increases due to decreased lung compliance.
d) Measures lung compliance, and the ratio increases due to increased lung capacity.

Answer 1

The FEV1/FVC ratio measures the forced expiratory volume in one second relative to total forced vital capacity, used to diagnose lung diseases. In lung fibrosis, the ratio increases due to the lungs becoming stiffer and less pliable, meaning decreased lung compliance.

Step-by-step explanation:

The ratio of FEV1/FVC measures the forced expiratory volume in one second (FEV1) relative to the forced vital capacity (FVC). In cases of lung fibrosis, the FEV1/FVC ratio will increase because lung fibrosis leads to decreased lung compliance. This means the lungs become stiffer and less able to expand and contract. As a result, although the total amount of air that can be forcibly exhaled (FVC) is reduced, the airways are not obstructed, so the person is able to expel air rapidly, leading to a relatively preserved or even increased FEV1/FVC ratio.

In summary, The correct answer is: b) Measures the forced expiratory volume in one second relative to forced vital capacity, and the ratio increases due to decreased lung compliance.