Respiration: Measuring Lung Capacity

Purpose In this lab you will measure your lung capacity using a Spirometer, and then compare this actual lung capacity with a calculated capacity for a person of your height and age.

Prelab: Create a hypothesis about lung capacity by choosing the best option below for each of the different variables. Write your hypotheses in complete sentences on your lab data sheet. a. A person that exercises frequently will have (the same or larger or smaller) lung capacity than someone that exercises rarely. b. A tall person will have (the same or larger or smaller) lung capacity than a short person. c. Exposure to cigarette smoke will (increase or decrease or not effect) lung capacity. d. Gender will (effect or not effect) lung capacity.

Personal Data: On your lab data sheet, write down some information that might affect your lung capacity. a. Gender (male or female) and age in years b. Approximate height in inches and convert to cm. c. Characteristics – use the following key to indicate personal characteristics that can affect lung capacity.  Exercise if you participate in a sport or exercise regularly on your own.  Music if you sing regularly or play a wind instrument in a band.  Smoke if you smoke cigarettes or are exposed to cigarette smoke on a regular basis.  Health if you have a health condition that might affect your lung capacity (flu, asthma, bronchitis, etc.)

Laboratory Investigation 1. Set the Spiro meter to zero. 2. Poke a finger-sized hole through a clean piece of plastic wrap and place it on the Spiro meter tube. 3. Inhale slowly and deeply, then place the Spirometer tube in your mouth and exhale all of your air. 4. Record your results on the data table for Trial 1. 5. Repeat steps 3 & 4 and record your results on the data table for Trial 2. 6. Calculate the average of your two trials, record the average on your data table, and then copy the average and your conditions onto the board.

Data Analysis: 1. Copy down all the data in the chart on your lab data sheet. Under “Characteristics” use the following abbreviations: M = male, F = female, E = exercise, U = music, S = smoke, H = health. Don’t forget to include each individual’s height and age. 2. Observe the data trends and pick 2 variables that affect lung capacity. 3. Write out a question that relates one variable to the other. For example: Do female athletes have a higher lung capacity than male athletes? 4. Write a hypothesis that answers your question. There must be at least 5 people with the characteristics that you are investigating. If only 2 people exercise regularly, then the example question would not be valid. 5. Identify all the members in each group and then separately calculate the average for the groups. In the example, all the female athletes would be averaged, and then all the male athletes would be averaged. 6. Title your graph. Label your y-axis with Liters and create an appropriate scale. 7. Draw 2 bars in different colors and label the bars on your x-axis. 8. Write a conclusion that describes the results of your analysis. Why is there a difference? What could account for it? Think about structures and mechanics of breathing, respiration and cellular respiration.