Physicians Routinely Give Their Patients Pulmonary Function Tests in Order

question 7

Multiple Choice

Physicians routinely give their patients pulmonary function tests in order to measure characteristics of lung function. The most common of these tests, spirometry, measures both the volume and the speed of air entering and exiting the lungs. In this test, a person first breathes normally while breathing into a spirometer, a machine that measures air volume and air speed. Then the person takes the deepest breath possible and exhales as hard as possible for 6 seconds into the spirometer. The resulting data are plotted on a graph of volume (y axis) versus time (x axis) . Spirometry is useful not only for assessing lung function in healthy patients but also for characterizing patients with lung conditions such as pulmonary fibrosis, asthma, or emphysema.
A sample graph for a healthy adult male is shown below. Normal breathing occurs between points A and B, a maximal inhalation occurs at point C, and a maximal exhalation occurs at point D. Normal breathing resumes between points E and F.

-For this data set, how much air is exhaled during a normal breath?

• A) 500 mL
• B) 1,200 mL
• C) 2,300 mL
• D) 2,800 mL

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Definitions:

Variability

A statistical measure that describes the dispersion or spread of data points in a data set.

Standard Deviation

A statistical measure of the dispersion or variability of a set of data points around their mean.

Mean Deviation

The average deviation for all scores from the mean of a distribution, calculated as the sum of the absolute value of the scores’ deviations from the mean divided by the number of scores.

Standard Deviation

Standard deviation is a measure of the dispersion or spread of a set of data points relative to its mean, indicating how spread out the data points are.