How the human body breaths
Carbon Dioxide
The respiratory system bring in the Oxygen through the mouth or nose . Humans breathe in Oxygen , approximately 20 times minute . As air breathed in , it passes through the back of the nose where dust and gases filtered . Two tubes branch off from the windpipe and go to each lung. When you breath out (exhale) , carbon dioxide is released - a natural by product . How most creature breath is quite similar except for that of birds . Technically speaking , even plants have respiratory systems , but they exhale Oxygen and inhale carbon dioxide . This is why plants are so important to out environment .They breath in the harmful carbondioxide that other mammals breathe out.