The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation). This exchange of oxygen and carbon dioxide is calledrespiration
When you breathe in (inhale), air containingoxygen enters your windpipe, passes throughthe bronchi and eventually reaches the air sacs. These air sacs, called alveoli, are responsible for gas exchange. They look a bit like grapes at the end of the bronchial branches.
