Your lungs are part of the respiratory system. Your respiratory system’s function is primarily twofold: to deliver oxygen into the blood and remove carbon dioxide.
Oxygen is a vital component in the life of a cell and carbon dioxide is its waste. Breathing is essentially inhaling oxygen and exhaling carbon dioxide. Your lungs and the rest of your respiratory system accomplish delivery and removal of these molecules in conjunction with your circulatory system.
In addition to the lungs, your respiratory system consists of the nose, nasal cavity, pharynx, larynx, trachea, bronchi and bronchioles. This system of respiration cleans, warms and moistens air on its way to your lungs.
Another participant in oxygen delivery and carbon dioxide removal process are muscles located along the bottom of the chest cavity, referred to as the diaphragm. When your diaphragm muscles contract oxygen is sucked into the lungs and upon relaxation carbon dioxide is expelled.