Gas Exchange

Gas exchange is the process where you inhale oxygen and exhale carbon dioxide. It all happens because of your lungs. The lungs are protected by the rib cage. The air you breathe in goes through your trachea (throat), which splits into two tubes called bronchi, with one going into each lung. The bronchi then split further into pipes called bronchioles. At the end of the bronchi are air sacks called the alveoli. It is here where gas exchange takes place.

Oxygen is inhaled into the lungs. Some of this oxygen is passed into the blood stream via diffusion (where particles move from an area of high concentration to an area of lower concentration), so that it can be used for respiration. Carbon dioxide is a waste product of respiration. This is passed into the lungs via diffusion and is breathed out. This all happens within seconds.