Subclavian aa.

The subclavian arteries are paired major arteries of the upper thorax (chest) that travel just posterior to the clavicle (collar bone). They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplies blood to the right arm, with some small branches supplying the head and thorax.

On the left side of the body, the subclavian comes directly off the arch of aorta. On the right side of the body, the subclavian arises from the relatively short brachiocephalic artery (trunk) along with the right common carotid artery.

The subclavian arteries are divided into three parts based on their relationships with the anterior scalene muscle. The usual branches of the subclavian arteries on both sides of the body are the vertebral artery, the internal thoracic artery, the thyrocervical trunk, the costocervical trunk and the dorsal scapular artery. The subclavian becomes the axillary artery at the lateral border of the first rib.