Oxygen Extraction by the Lungs
Recommended for grades 9–12.
Introduction
Oxygen is required for cell metabolism. During inhalation air is brought into the lungs, where oxygen is extracted. Oxygen passes into the bloodstream at the membrane between the alveoli and pulmonary capillaries. The quantity of oxygen extracted from the air is dependent on the composition of the air and on the efficiency of the lungs. The percent concentration of oxygen in air on earth is almost uniformly 21% between sea level and the stratosphere. At sea level the density of the air (molecules/unit volume) is greater than it is at higher altitudes, allowing a greater number of molecules to be inhaled with each breath.
In this experiment, you will observe the quantity of oxygen that is absorbed from inhaled air by measuring the concentration of oxygen remaining in exhaled air. Successive breaths will further lower the oxygen concentration, allowing you to observe the efficiency of oxygen extraction by the lungs at lower oxygen concentrations.
Objectives
In this experiment, you will
- Measure the concentration of exhaled oxygen.
- Observe the efficiency of oxygen extraction by the lungs as the inhaled oxygen concentration is reduced.
Sensors and Equipment
This experiment requires each of the following Vernier sensors and equipment (unless otherwise noted):
Additional Requirements
You may also need an interface and software for data collection. What do I need for data collection?
Download Experiment Preview
The student-version preview includes:
- Step-by-step instructions for computer-based data collection
- List of materials and equipment
Note: The experiment preview of the computer edition does not include essential teacher information, safety tips, or sample data. Instructions for Logger Pro and other software (such as LabQuest App or TI handheld software, where available) are on the CD that accompanies the book. We strongly recommend that you purchase the book before performing experiments.
Standards Correlations
See all standards correlations for Human Physiology with Vernier »
Included in the Lab Book
Vernier lab books include a CD with word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.