Measuring Vital Capacity-- Stretch a round balloon several times to stretch it out. The lungs are part of our breathing system which has two functions:. This represents the action of the diaphragm and the inflation of the lungs. Lab: Balloons and Lung Capacity Experiment BACKGROUND: Your respiratory system is a group of organs that work together to take oxygen into your body and get rid of carbon dioxide. Today we’re going to find our how lungs work by making a lung model.. Carefully pull the balloon at the base of the bottle up and down and watch as the other balloon inflates. Your body can complete this process by both breathing and respiration. 2. To make sure that your chest doesn’t explode, the air gets forced back out through your mouth and nose. You will be using the diameter of a balloon and the graph shown to estimate your capacities. The lungs are an essential organ to all mammals. 1. When you exhale your diaphragm relaxes which decreases the volume of your lungs and increases the pressure in your chest. This is a neat experiment to watch as the balloon lung expands when filled with air. Take a deep breath and then exhale into the balloon. Breathing is the physical process of inhaling and exhaling. ventilation – the movement of air into and out of the lungs; gas exchange – this is where gases are exchanged between tiny sacs called alveoli and the blood. Your lungs are like the balloon and the diaphragm is like the balloon membrane at the base of you bottle. Our lungs work in a similar way: Air is taken in through our mouth and nose which is then passed through our windpipe and throat (like the straw takes in air when the balloon at the bottom of the plastic bottle is pulled), Choose 3 subjects from your group and record data on their height, age, sex, and activity level.