The lungs are located in the chest cavity of the body, on either side of the mediastinum. The mediastinum is formed by the trachea, esophagus, and large blood vessels. It is located in the center of the body and the lungs are located on either side of the mediastinum, which is subdivided into the left and right lungs. The lungs in the human body are in the chest cavity and have five lobes. The left lung is narrow and long and is divided into two lobes. The right lung is wide and short and is divided into three lobes. The left lung lobe is divided into upper and lower lobes by oblique fissures, and the right lung lobe is divided into upper, middle, and lower lobes by horizontal fissures, with the right middle lobe being smaller than the other four lobes. Between the two lungs are the heart and large blood vessels, trachea, esophagus, and other organs. The underside of the lungs are separated from the abdominal organs by the diaphragm. Outside the lungs is the plasma membrane, also known as the dirty pleura, which is smooth and moist. The lungs are soft and elastic, containing air and are spongy. Lung color darkens with age.