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How are the right and left lungs different in size and number of lobes?

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Medical illustration of the human chest showing the lungs, diaphragm, ribs, trachea, bronchus, and bronchioles, with one lung cut away to reveal internal structures. — human respiratory system The lungs serve as the gas-exchanging organ for the process of respiration.

The right and left lungs are slightly unequal in size and structure due to the asymmetrical placement of the heart within the chest cavity.12

Right Lung: This lung is larger, representing approximately 56 percent of the total lung volume. It is composed of three major lobes—the superior, middle, and inferior lobes—which are separated by horizontal and oblique fissures.21
Left Lung: This lung is smaller in volume to accommodate the heart. It consists of only two lobes, which are separated by a single oblique fissure.12

Internally, these lobes are further subdivided into smaller units known as pulmonary segments, with 10 segments typically found in the right lung and eight to 10 in the left lung.3