Using a Spirometer
Using a spirometer to investigate human lung function
The purpose of this activity is:
• to show how a spirometer can be used to find the vital capacity of lungs and to calculate important subdivisions of this capacity. • to show how to interpret the trace resulting from use of a spirometer • to consider how to use a spirometer to estimate metabolic rate.
Procedure
SAFETY:
Do not use a spirometer unless supervised by a teacher.
If you are using the spirometer and you experience any distress or difficulty breathing, remove the nose-clip and mouthpiece and detach yourself from the machine immediately.
Do not use the spirometer for more than a few minutes at a time.
[pic]
© Nuffield 1996
QUESTIONS
1. As a subject breathes in from the apparatus, what will happen to the lid of the chamber? If a pen or datalogger is attached to the lid, how will the trace it makes change as the subject breathes in?
2. As a subject breathes out into the chamber, what will happen as the air goes through the carbon dioxide absorbent granules?
3. Will the lid go back up to its starting position if the subject breathes out normally?
4. As the subject breathes steadily, they will use up oxygen and replace it with carbon dioxide. What will happen to the total volume of air in the spirometer?
Investigation: collecting data about normal breathing
a. Under your teacher’s supervision, collect data by making a trace as a subject breathes normally for 5-10 breaths.
b. After a normal out breath, ask the subject to breathe in as far as possible for one in breath, then breathe normally for two or three breaths.
c. After a normal in breath, ask the subject to breathe out as far as possible. They don’t have to breathe out quickly, but get them to try to breathe out as much as they can.
d. After this maximum out breath, ask the subject to breathe normally for another 5-10 breaths. After an out breath, disconnect them from the spirometer.
The purpose of this activity is:
• to show how a spirometer can be used to find the vital capacity of lungs and to calculate important subdivisions of this capacity. • to show how to interpret the trace resulting from use of a spirometer • to consider how to use a spirometer to estimate metabolic rate.
Procedure
SAFETY:
Do not use a spirometer unless supervised by a teacher.
If you are using the spirometer and you experience any distress or difficulty breathing, remove the nose-clip and mouthpiece and detach yourself from the machine immediately.
Do not use the spirometer for more than a few minutes at a time.
[pic]
© Nuffield 1996
QUESTIONS
1. As a subject breathes in from the apparatus, what will happen to the lid of the chamber? If a pen or datalogger is attached to the lid, how will the trace it makes change as the subject breathes in?
2. As a subject breathes out into the chamber, what will happen as the air goes through the carbon dioxide absorbent granules?
3. Will the lid go back up to its starting position if the subject breathes out normally?
4. As the subject breathes steadily, they will use up oxygen and replace it with carbon dioxide. What will happen to the total volume of air in the spirometer?
Investigation: collecting data about normal breathing
a. Under your teacher’s supervision, collect data by making a trace as a subject breathes normally for 5-10 breaths.
b. After a normal out breath, ask the subject to breathe in as far as possible for one in breath, then breathe normally for two or three breaths.
c. After a normal in breath, ask the subject to breathe out as far as possible. They don’t have to breathe out quickly, but get them to try to breathe out as much as they can.
d. After this maximum out breath, ask the subject to breathe normally for another 5-10 breaths. After an out breath, disconnect them from the spirometer.