Gas Exchange - Activity

Activity 4: Blow It Up!

Orientation

This activity focuses on measuring respiratory values. By measuring lung capacities and respiratory rates, the students will use the resulting data to first predict, then test their hypothesis. Various graphs can be charted from the results giving students the opportunity to practice graphing different types of graphs, as well as gleaning conclusions from the data analysis.

Materials

1 balloon for each student

Flexible measuring tape

Measuring stick/Ruler

Lung Capacity Data Sheets

Student Journal

Measuring respiratory values not only helps us understand how the lungs work, but it also can help doctors determine if a patient might have lung disease. In this activity, we will measure vital capacity using balloons and then compare these values to our fellow classmates. Vital capacity is the volume of air that can be expelled after a full inhalation. The total air holding capacity of the lung is the sum of the vital capacity and the residual volume. Even when you try extremely hard to expel all of the air in your lungs, there is still some air left in the alveoli and airways. If there wasn't, then your alveoli and airways would collapse!! If you would like to make your own spirometer to measure vital capacity, see Activity 1 of this module.

Sit down and take deep breaths in and out five times.
Breath in, as deeply as possible.
Hold a balloon to your mouth, tightly sealing the opening, and blow all the air out of your lungs.
Take the balloon out of your mouth, taking care to keep the opening sealed tightly.
Continue holding the balloon while your partner measures the girth of the balloon (in centimeters). The girth is the circumference of the widest part of the balloon.
Record this value down on TABLE A as the Vital Capacity Girth.
Breathe in and out normally. Have your partner count the number of breaths you take in 30 seconds. (1 breath = breathing in and then out).
Double this number to obtain the breaths taken in 1 minute and record this number on TABLE A as the Resting Respiratory Rate.
With your partner timing you, run in place for 1 minute.
At the end of one minute, sit down to have your elevated respiratory rate measured. (Partner: As soon as the student sits down, measure the number of breaths the student takes in 30 seconds.)
Double this number to obtain the breaths taken in 1 minute and record this number on TABLE A as the elevated respiratory rate.
Measure your partner's height in inches and record his/her height and gender on TABLE A.
Record your values, and use your values from TABLE A to fill out TABLE B.

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