False-colour version of an engraving of the venous system from De Humani Corporis Fabrica (On the Structure of the Human Body) by Andreas Vesalius, first published in 1543. The original black & white drawing was captioned A delineation of the entire vena cava freed from all its parts". Following traditional views, the venous system is depicted as a single continuous vessel. It is not clear who did many of the drawings; some scholars believe Titian may have been involved & certainly Jan van Kalkar & Domenico Campagnola contributed."