The tissue of the lungs is divided by deep fissures into sections called lobes . The right lung has three lobes and the left lung has two lobes - you can see these on the diagram.

There are two main bronchi which conduct air from the trachea into the lungs - one to the left and the other to the right.

Each lung is enclosed within a two-layered membranous sac called the pleura . The outer layer is called the parietal pleura and adheres closely to the chest wall and diaphragm. The inner layer – the visceral pleura – clings closely to the lungs.