Measuring Lung Capacity Lab
Name_________________________________________ Date _______ Class _____
Background
Human lung capacity can be measured in several ways. One way is by using a complex piece of
laboratory equipment called a spirometer. However, lung capacity can also be measured by using a
balloon.
Several different lung volume measurements can be made. The amount of air taken in or expelled
during normal breathing is about 500 cm3. This volume of air called the tidal volume. This amount of air
provides enough oxygen for a person who is resting. The largest possible amount of air which can be
exhaled after drawing in a deep breath is the vital capacity. The amount of air that remains in the lungs
after exhaling normally but which can be expelled is the expiratory reserve. A certain amount of air in
the lungs cannot be expelled. This is the residual volume.
Purpose
-To measure your vital capacity
-To make comparisons among factors that may affect vital capacity
-To compare your experimental data with lung capacity data obtained from a spirometer
Materials
Round Balloon
Metric Ruler
Procedure
Part A: Measure your Height in centimeters: ___________
Part B. Vital Capacity




Stretch a balloon several times
Take as deep a breath as possible. Then exhale all the air you can into the balloon.
Measure and record the diameter of the balloon in Table 4-1.
Run four more trials. Record the diameter of the balloon for each trial in the data table.
Figure 6-1
Part C. Conversion of Diameters to Volume
Lung volume is expressed in cubic centimeter units (cm3). (1,000 cm3 is slightly more than a quart.)

To convert from balloon diameter to volume, locate the balloon diameter on the horizontal axis
of Figure 6-2. Follow this number up to the heavy line, then move across to locate the
corresponding volume.
For example, if your balloon diameter is 14.5 cm, then the corresponding lung volume is
1500 cm3.


Convert each diameter for vital capacity to volume.
Record the volumes in Table 4-1.

Calculate and record your average vital capacity
Data/Results
Table 4-1
Figure 6-2
Vital
Capacity
Balloon Diameter
(cm)
Lung Volume from Graph
(cm3)
Trail 1
2
3
4
5
Total
Average
Part D. Comparing Vital capacity
Table 4-2: Lung Volumes of Females and Males based on Height
In the table below collect the height and lung capacity of the males and females in your classroom.
Graph your data. (Use 2 different colors to represent gender)
Data Table:
Lung
Capacity: Height :
Males
Male
(x-axis)
(y-axis)
Graph:
Height :
Lung
Capacity: Female
Females
(x-axis)
(y-axis)
Height
(cm)
Lung Volume: Vital capacity
(cm3)
Table 4-3:
Average Lung Volumes
Male (cm3)
Vital Capacity
5,000
Female (cm3)
4,000
Listed in Table 4-3 are “average” male and female lung volume measurements. The volumes were
determined by using a spirometer.
Discussion:
1. How does your vital capacity compare to the average lung capacity determined by using a
spirometer?
2. What are three things that could be affecting your lung capacities?
3. How do males vital capacity compare with female vital capacity?
4. How might an athlete's vital capacity compare to a non-athlete? Explain your reasoning.
5. How might vital capacity be important to a musician?
Examine the data table of a person who entered into a training program. This person's vital capacity was
measured over a 60 day period.
Data
Day of Training
0
10
20
30
40
50
60
Vital Capacity
4800
4840
4890
4930
4980
5180
5260
6. What happened to the person's vital capacity over the
course of the training period?
7. What probably caused the change?
8. At the respiratory surface, what process actually causes O2 to go into the blood and CO2 to go out of
the blood? (Hint: Hopefully, there is a higher concentration of O2 in the air you breathe, than in the
blood when you inhale.)
9. What is the benefit of having so many tiny alveoli rather than one big air sac?
10. How does the Respiratory System serve the needs of cells?
11. What is cellular respiration? How is it connected to this organ system?
12. Design an investigation to test one of the following:
 Do you think the air temperature will have an effect on the lung capacity of an individual?
 Will a person's height and/or size have an effect on their lung capacity?
 How does a smoker vs. nonsmoker compare for lung capacity?
a) Write a step-by-step procedure for the investigation.
b) Create a chart to record the type of data you would collect in your investigation.
Write your procedure & chart on a separate sheet of paper and staple to the back of this lab.