Vein in Root of Neck

The subclavian vein, the continuation of the axillary vein, begins at the lateral border of the 1^st rib and ends when it unites with the IJV. The subclavian vein passes over the 1^st rib anterior to the scalene tubercle parallel to the subclavian artery, but it is separated from it by the anterior scalene muscle. It usually has only one named tributary, the EJV.