The subclavian veins are large blood vessels located beneath the collarbone, or clavicle. They play a crucial role in returning deoxygenated blood from the arms and upper body back to the heart. Each subclavian vein is paired with a corresponding subclavian artery, which carries oxygen-rich blood to the same regions. These veins are formed by the merging of the internal jugular vein and the brachiocephalic vein. They travel towards the chest, where they join the brachiocephalic veins to form the superior vena cava, ultimately directing blood into the right atrium of the heart.