1. The Human Lung The lungs are a place for your blood to receive oxygen and get rid of carbon dioxide made by the cells in your body. When you breathe in, a muscle called the diaphragm contracts, allowing your lungs to fill with air. When you breathe out, the diaphragm expands, pushing out the air in the lungs.

2. How Much Can Your Lungs Hold? Devices called spirometers are used to test lung capacity. Several different factors determine lung capacity: Larger volumesSmaller volumes malesfemales taller peopleshorter people non-smokerssmokers athletesnon-athletes people living at high altitudespeople living at low altitudes The average adult male has a total lung capacity of about 6 liters, or 10 20 oz. Coke bottles. Peter Reed, a British rower, has a the largest total lung capacity recorded of 11.68 liters, or 19.7 20 oz. Coke bottles!

3. Average Numbers for Children – Expiratory Flow One instrument measures peak expiratory flow, or how much air you can blow out at once. Predicted Average Peak Expiratory Flow of Normal Children and Adolescents Height FlowHeight FlowHeight FlowHeightFlow 43''14749''22755''30761''387 44''16050''24056''32062''400 45''17351''25457''33463''413 46''18752''26758''34764''427 47''20053''28059''36065''440 48''21454''29360''37366''454

4. Average Numbers for Children – Vital Capacity The other instrument measures normal vital capacity, or how much air your lungs can hold. Normal Vital Capacities for Boys 5-17 HeightCapacityHeightCapacityHeightCapacity 42''90849''156656''2240 43''100250''166057''2318 44''109651''175458''2412 45''119052''184859''2506 46''128453''1942 47''137854''2036 48''147255''2130 Normal Vital Capacities for Girls 5-17 HeightCapacityHeightCapacityHeightCapacity 42''86449''140356''1942 43''94150''148057''2019 44''101851''155758''2096 45''109552''163459''2173 46''117253''1711 47''124954''1788 48''132655''1865 Capacities are in mL