LUNGS

  Either of a pair of highly elastic, spongy organs in the chest that are the main organs of respiration, inhaling air from which oxygen is taken and exhaling carbon dioxide. The lungs are compose of lobes, the right lung with three, the left with two. The lobes are divided into lobules, each of which contains blood vessels, lymphatics, nerves and ducts connecting the alveoli, or air spaces, where the actual oxygen-carbon dioxide exchange takes place.