Subclavian artery

Subclavian artery
Schematic of the proximal aorta and its branches. The left subclavian artery is the fifth branch of the aorta and the third branch from the arch of the aorta. The right subclavian artery arises from the brachiocephalic artery (labeled 'innominate' on diagram).
The arch of the aorta, and its branches. (Rt. subclavian is at upper left, and lft. subclavian is at upper right.)
Details
Source	aortic arch (left) brachiocephalic (right)
Branches	vertebral artery internal thoracic artery thyrocervical trunk dorsal scapular artery (mostly)
Vein	subclavian vein
Identifiers
Latin	arteria subclavia
MeSH	A07.231.114.839
Dorlands /Elsevier	a_61/12156042
TA	A12.2.08.001
FMA	3951
Anatomical terminology []

In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. 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 branches supplying the head and thorax. On the left side of the body, the subclavian comes directly off the arch of aorta, while on the right side it arises from the relatively short brachiocephalic artery when it bifurcates into the subclavian and the right common carotid artery.

The usual branches of the subclavian on both sides of the body are the vertebral artery, the internal thoracic artery, the thyrocervical trunk, the and the dorsal scapular artery, which may branch off the transverse cervical artery which is a branch of the thyrocervical trunk. The subclavian becomes the axillary artery at the lateral border of the first rib.

From its origin, the subclavian artery travels laterally, passing between anterior and middle scalene muscles, with the anterior scalene (scalenus anterior) on its anterior side and the middle scalene (scalenus medius) on its posterior. This is in contrast to the subclavian vein, which travels anterior to the scalenus anterior. As the subclavian artery crosses the lateral border of the first rib, it becomes the axillary artery.

On the right side the subclavian artery arises from the brachiocephalic (innominate) artery behind the right sternoclavicular articulation; on the left side it springs from the arch of the aorta. The two vessels, therefore, in the first part of their course, differ in length, direction, and relation with neighboring structures.