Expansion
It crosses the midline behind the manubrium to reach the superior vena cava
Expansion
- Right brachiocephalic vein - short, about 2.5 cm, descending almost vertically
- Left brachiocephalic vein - long, about 6 cm, passing obliquely behind the manubrium to join its fellow
The two unite behind the first right costal cartilage to form the superior vena cava. The asymmetry mirrors that of the arteries: the heart sits to the left, so left-sided venous structures must travel further to reach it.
Two practical consequences: a central venous catheter placed from the left has to negotiate this transverse course, which is why left-sided lines more often abut the vessel wall; and the thoracic duct drains into the left venous angle at the origin of this vein.