Inhalation

Inhalation is half of what occurs when people or animals breathe. Air is moved from the outside through the respiratory system into the lungs. The lungs take out some oxygen and put it into the blood. Drugs can also be inhaled with an inhaler to put them into the blood. The air is then moved out of the lungs again. This is the other half of breathing, called exhalation.

This short article about biology can be made longer. You can help Wikipedia by adding to it.