The thoracic aorta is a special region of the descending aorta as it passes through the mediastinum of the thorax. Superiorly (upward), the thoracic aorta is continuous with the aortic arch and inferiorly (downward), it becomes the abdominal aorta as passes through the diaphragm.

The thoracic aorta supplies oxygenated blood to the pericardium, esophagus, bronchi, and lungs via visceral branches (i.e., vessels that supply blood to internal organs such as the lungs). Another set of branches, the parietal branches (i.e., vessels that supply blood to the walls of a body cavity such as the thorax or particular organ), supply oxygenated blood to the thoracic cavity.

Mediastinal branches of the thoracic aorta supply blood to the lymph nodes and surrounding tissue in the mediastinum. Short and small diameter phrenic branches from the lowest (most inferior) regions of the thoracic aorta supply...