According to the Canadian Lung Association, the lungs deliver oxygen to the body and remove carbon dioxide and other waste gases that the body does not need. The National Heart, Lung and Blood Institute states that the lungs lie on both side of the breastbone, and they fill the inside of the chest cavity. The left lung is smaller than the right lung to provide space for the heart.
Hillendale Health notes that the lungs are the primary organs of the respiratory system. Oxygen is brought into the lungs and into the body while carbon dioxide is exhaled. The red blood cells acquire the oxygen in the lungs and carry it to the body cells that need oxygen. The red blood cells then take the carbon dioxide produced by the cells and transport it back to the lungs where it is breathed out of the body.
The NHLBI explains that the lungs are divided into five sections called lobes. Within the lungs, the bronchi branch into thousands of tiny, thin tubes called bronchioles with round air sacs known as alveoli at the end of the tubes. These air sacs are covered by small blood vessels called capillaries, which connect to a network of veins and arteries that move blood throughout the body.