the curved portion of the aorta between its ascending and descending parts; it begins as a continuation of the ascending aorta posterior to the sternal angle, runs posteriorly and slightly to the left as it passes over the root of the left lung, and becomes the descending aorta as it reaches and begins to course along the vertebral column; it gives rise to the brachiocephalic trunk, the left common carotid, and the left subclavian arteries; SYN: arcus aortae [TA], aortic arch.
