Your lungs are the major organs that help with breathing. They are part of the body’s respiratory system All animals that have a backbone and breathe air have lungs. When an animal breathes in, air filled with oxygen flows into the lungs. When an animal breathes out, a gas called carbon dioxide and water vapor flow out of the lungs.
A body has two lungs, one on each side of the chest. The heart is located between the lungs. The right lung has three rounded sections called lobes. The left lung has two lobes. The base of each lung rests on a strong sheet of muscle called the diaphragm. In normal breathing the diaphragm and the muscles between the ribs automatically tighten and relax. This movement helps the lungs to fill with air and to empty.
Air enters and leaves the lungs through a series of tubes. A large, tough tube called the trachea, or windpipe, connects the top of the throat to two branching tubes called bronchi. Each of these tubes leads to a different lung.
