Coloured 3D computed tomography (CT) scan of the chest of a patient with the bovine aortic arch variant. The aorta is the main artery that carries blood from the heart to the rest of the body. As it leaves the heart, it arches over the top of it. There are usually three arteries that branch from the aortic arch. However, in the case of a bovine aortic arch the second artery, the left common carotid artery, branches from the first artery, the brachiocephalic artery, rather than from the aortic arch. This is the most common anatomic variant of the aortic arch is usually asymptomatic.