Upper venous system. Schematic of the central upper venous system with examples of a right internal jugular vein CVL (1), a left internal jugular vein CVL (2), and a right subclavian CVL (3). R indicates right; L, left; IJV, internal jugular vein; SCV, subclavian vein; BCV, brachiocephalic vein; and SVC, superior vena cava.