Branching from the aortic arch of the ascending aorta, the subclavian arteries, as their name specifies, run below the clavicle. The right subclavian artery normally splits from the brachiocephalic trunk off the aortic arch of the ascending aorta. The left subclavian artery, however, usually splits directly from the aortic arch of the ascending aorta.

The subclavian arteries ultimately provide the origin of the thyrocervical and costocervical trunks of the internal thoracic arteries, and origin of the vertebral arteries. Accordingly, the left and right subclavian arteries ultimately supply oxygenated blood to the internal thoracic region (including the thoracic wall and internal thoracic region), parts of the upper arm (upper limb), neck, spinal cord, meninges, and brain. The internal thoracic arteries supply blood to the diaphragm, mediastinal structures, and the anterior thoracic wall.

After branching into the internal thoracic and vertebral arteries, the subclavian arteries run to the...