Jugular vein
The jugular vein was a  in the humanoid neck. 

In 2152, while being quizzed on Human anatomy by Doctor Phlox, Cutler identified the external jugular as being connected to the superior vena cava, which in turn was connected to the heart. ()

In 2369, in "Takaran Anatomy" for Doctor Jo'Bril, the jugular vein was listed under lateral sternal in the graphic. ()

External link 
 
Anatomy