Bronchial artery


In human anatomy, the bronchial arteries supply the lungs with nutrition and oxygenated blood. Although there is much variation, there are usually two bronchial arteries that run to the left lung, and one to the right lung.

Structure

The left bronchial arteries usually arise directly from the thoracic aorta.
The single right bronchial artery usually arises from one of the following:
The bronchial arteries supply blood to the bronchi and connective tissue of the lungs. They travel with and branch with the bronchi, ending about at the level of the respiratory bronchioles. They anastomose with the branches of the pulmonary arteries, and together, they supply the visceral pleura of the lung in the process.
Note that much of the oxygenated blood supplied by the bronchial arteries is returned via the pulmonary veins rather than the bronchial veins. As a consequence, blood returning to the left heart is slightly less oxygenated than blood found at the level of the pulmonary capillary beds.
Each bronchial artery also has a branch that supplies the esophagus.

Comparison with pulmonary arteries

It is easy to confuse the bronchial arteries with the pulmonary arteries, because they both supply the lungs with blood, but there are important differences:

Clinical significance

The bronchial arteries are typically enlarged and in chronic pulmonary thromboembolic hypertension.
With modern surgical techniques, bronchial anastomoses heal well without bronchial artery reconnection. Largely for this reason, bronchial artery circulation is usually sacrificed during lung transplants, instead relying on the persistence of a microcirculation presumably arising from the deoxygenated pulmonary circulation to provide perfusion to the airways.
Aneurysms of the bronchial artery may mimic aortic aneurysms.
The bronchial arteries and their supply of nutrients to the lungs are also attributed to the observation that an occluded pulmonal artery very rarely results in lung infarction.