he right lung is divided into three different sections, called lobes. The left lung has just two lobes. The lobes are made of sponge-like tissue that is surrounded by a membrane called pleura, which separates the lunges from the chest wall. Each lung half has its own pleura sack. This is why, when one lung is punctured, the other can go on working.
The lungs are like bellows. When they expand, they pull air into the body. When they compress, they expel carbon dioxide, a waste gas that bodies produce. Lungs do not have muscles to pump air in and out, though. The diaphragm and rib cage essentially pump the lungs.