The subclavian veins are two large veins, one on either side of the body. Their diameter is approximately that of the smallest finger. Each subclavian vein is a continuation of the axillary vein and runs from the outer border of the first rib to the medial border of anterior scalene muscle. From here it joins with the internal jugular vein to form the brachiocephalic vein (also known as "in-nominate vein"). The angle of union is termed the venous angle. The subclavian vein follows the subclavian artery and is separated from the subclavian artery by the insertion of anterior scalene. Thus, the subclavian vein lies anterior to the anterior scalene while the subclavian artery lies posterior to the anterior scalene (and anterior to the middle scalene).