Your lungs are sponge-like, elastic organs which absorb the oxygen you breathe in (inspiration) from the air, and allows the carbon dioxide waste produced by your body to be eliminated as you breathe out (expiration).
You have a left and right lung, found in the chest cavity. The trachea (“windpipe”) directs the air you breathe from your mouth and nose into the lungs. The trachea separates into a right and left pathway (bronchus), and then into progressively smaller paths to distribute the air to all areas of the left and right lungs. Each lung is formed by a series of lobes containing alveoli – small sac-like structures that provide a place for blood to come in close contact with the oxygen you breathe in. “Gas exchange” occurs at the alveoli, with oxygen passing into your bloodstream and carbon dioxide passing out to be expelled from your mouth and nose during expiration.