For a gas exchange system to work efficiently you need a steep concentration gradient. Humans, like many big, complex mammals, move air in and out of the lungs regularly. They maintan a steep concentration gradient of both oxygen in and carbon dioxide out. This is known as ventillation the lungs or breathing. It takes place in your specially adapted breathing systems.
The breathing system
Your lungs are fouynd in your chest or thorax and are protected by your bony ribcage. They are separated from the digestive organs beneath (in your abdomen) by the diaphragm. The diaphragm is a strong sheet of muscle. The job of your breathing system is to move air in and out of your lungs. The lungs provide an efficient surface for gas exchange (in the alveoli).
Moving air in and out of the lungs
Ventilation of the lungs is brought about by movement of your…