arch of the aorta, the proximal one of the four portions of the aorta, giving rise to three arterial branches, called the brachiocephalic, left common carotid, and left subclavian arteries. The arch rises at the level of the border of the second sternocostal articulation of the right side, passes to the left in front of the trachea, bends dorsally, and becomes the descending aorta. Also called aortic arch.
