The right lung is larger than the left lung because it has three lobes. In contrast, the left lung has only two lobes. The lungs have a conical shape.
The right lung consists of the upper lobe, middle lobe and lower lobe. The lower lobe, the largest of the three, is separated from the upper and middle lobes by a fissure. The upper lobe makes up approximately one-third of the right lung. The left lung has upper and lower lobes that are also separated by a fissure. The lobes of both lungs work to expel carbon dioxide from the body and ensure the organs receive an adequate supply of oxygen.