The lungs are provided by 2 sets of arteries, viz.
A. Bronchial arteries.
B. Pulmonary arteries.
The bronchial arteries provide nourishment to the bronchial tree and pulmonary tissue.
The right lung is provided by 1 bronchial artery, which originates from the right third posterior intercostal artery or from upper left bronchial artery. The left lung is provided by 2 bronchial arteries, which originate from descending thoracic aorta.
The pulmonary arteries provide deoxygenated blood to the lungs. There’s 1 pulmonary artery for every lung. They may be the branches of the pulmonary trunk.
The left and right pulmonary arteries be located anterior to the main (primary) bronchi as they goes into the hilum of their respective lungs. The right pulmonary artery is crossed superiorly by the arch of the azygos vein; on the other hand the left pulmonary artery is located inferior to the arch of aorta, in the level of T5 vertebra. The pulmonary arteries split into lobar branches in the hilum and afterwards split into terminal/ segmental branches. The segmental branches, branch successively corresponding with the segmental branches of the bronchial tree.