to inhale and exhale more forcefully the maximum amount of air moved in and out of the lungs is called the VITAL CAPACITY which is the amount of air a person can expel from the lungs at maximum inhalation Materials Balloons metric ruler meter stick Prediction Which factor s have the most affect a person s vital capacity Rank in order from MOST effect 1 to least effect 5 The weight of the person The sex of the person Activity level athletics PROCEDURE Consider the factor you think will have the greatest effect on both vital capacity and tidal volume Explain your choice In this activity you will be measuring the vital capacity of members of the class If you have any breathing difficulties asthma or other condition you should not participate You will be using the diameter of a balloon and the graph shown to estimate your capacities 1 Choose 3 subjects from your group and record data on their height age sex and activity level The height of the person The age of the person 2 Measuring Vital Capacity Stretch a round balloon several times to stretch it out Take a deep breath and then exhale into the balloon Pinch the end of the balloon and measure its diameter in cm Record on data table 3 Convert the diameter to volume using the graph and record this on your table 4 Estimated Vital Capacity Research has shown that the capacity of a person s lungs is proportional to the surface area of his body and his height This online calculator will use your height and age to estimate your vital capacity Have each of your subjects record their data Go to this site http biol co vitcap1 DATA TABLE Subject 1 Subject 2 Subject 3 Subject 4 Sex Height Age Subject Data Lung volume cubic centimeters 8000 7000 6000 5000 4000 3000 2000 1000 0 Metric ruler Diameter 2 4 6 8 10 12 14 16 18 20 22 24 Baloon diameter centimeters and input information on test subjects It will calculate the vital capacity Activity Level low medium high Balloon Diameter Vital Capacity Volume from graph Volume from Calculator ANALYSIS 1 What is the difference between tidal volume and vital capacity Suggest a way you could measure a person s tidal volume