Picture of Lungs
The lungs are organs used for breathing located on either side of the chest. The lungs fill with air, oxygenate the blood, and dispose of carbon dioxide. Lungs are comprised of many different structures. The image on this page depicts the trachea, bronchi, and the several lobes of the left and right lungs.
The trachea (windpipe) is the passageway that allows air to travel to and from the lungs. The structure of the trachea is supported by rings of cartilage that keep it from collapsing. The bottom of the trachea bifurcates into two bronchi; one each leading to the left and right lungs. Each bronchi further splits into smaller and smaller tubes, comprising the bronchial tree. The larger bronchi are supported by rings of cartilage, while the smaller bronchioles do not have rings and are very elastic, which allows them to stretch as the lungs expand and contract.
Each lung is divided into lobes. The right lung has two lobes: the upper, middle, and lower lobes. The left lung is slightly smaller due to the presence of the heart on that side of the chest. The left lung is comprised of two lobes, the upper and lower.
Text Reference: National Cancer Institute: "Anatomy of the Lung"