The pulmonary system
The lungs are the main organ of the pulmonary system.
Everywhere she went, she pulled her money (pulmonary) with her, which made it hard on her lungs.
The pulmonary system is the part of the cardiovascular (blood circulation) system that carries deoxygenated blood (blood that contains no oxygen) away from the heart to the lungs, and returns oxygen-rich blood to the heart. The lungs are the organs that put oxygen into the blood, so are key to the system.