What connects the respiratory and circulatory system?

The respiratory and circulatory systems are connected through the pulmonary circulation. Pulmonary circulation is the movement of blood between the heart and the lungs. During pulmonary circulation, deoxygenated blood travels from the heart to the lungs, where it becomes oxygenated, and then returns to the heart.

-Pulmonary artery: carries deoxygenated blood from the right ventricle of the heart to the lungs.

-Pulmonary veins: return oxygenated blood from the lungs to the left atrium of the heart.