FIG 4. Left lateral view of the sigmoid sinus/jugular bulb junction. The mastoid emissary vein (n) and lateral (h) and posterior (g) condylar veins are shown. The plexiform nature of the vertebral artery venous plexus (j), shown here around the horizontal portion of V3, is well seen. c, sigmoid sinus; a, superior jugular bulb; v, pterygoid plexus; u, internal jugular vein.