The right lung consists of three lobes:

• superior lobe
• inferior lobe
• middle lobe.

These lobes are separated by two fissures, known as the oblique fissure and the horizontal fissure.

The oblique fissure separates the middle and inferior lobes, whereas the horizontal fissure separates the superior and middle lobes.

Pictured here is the middle lobe of the right lung.

The left lung, on the other hand only has two lobes separated by one fissure. The superior lobe is separated from the inferior lobe by the oblique fissure.

Learn more about the respiratory system in this tutorial.