Bronchial branches of aorta

The bronchial branches of aorta (more commonly termed as "bronchial arteries") are the systemic arteries that supply oxygenated blood to the airways, supporting structures of the lungs, and, to a lesser extent, the visceral pleura. Their anatomy is highly variable, but several consistent features are recognized.

• Origin: Most commonly, the bronchial arteries arise from the descending thoracic aorta between the T5 and T6 vertebral levels. The typical pattern is one right and one left bronchial artery, but the number can range from one to six, with multiple anatomical variants described. The right bronchial artery often originates as a common trunk with a posterior intercostal artery, termed the right intercostobronchial trunk. Ectopic origins are not rare and may include the aortic arch, subclavian artery, or other branches.

• Course: After originating from the aorta or its branches, the bronchial arteries course through the mediastinum. The left bronchial artery usually passes anterior to the esophagus to reach the left hilum, while the right bronchial artery may pass either anterior or posterior to the esophagus, depending on its origin.The arteries then enter the hilum and follow the bronchi, supplying the bronchial walls, peribronchial tissues, and adjacent lymph nodes.

• Distribution: The bronchial arteries form anastomoses with the pulmonary arteries near the respiratory bronchioles, contributing to collateral circulation in certain pathological states.

• Diameter and Number: The diameter of bronchial arteries is typically 1–2 mm, but can be larger in cases of hypertrophy due to chronic lung disease or vascular anomalies.