Venous drainage in the craniocervical region.

The venous drainage of the craniocervical junction is made up of jugular veins and particularly the vertebral veins and their anastomoses. The anterior and posterior condylar veins join to form the plexus of the vertebral vein, the supply functions of which can be modified by the presence of the mastoid anastomotic emissary veins which increase the possibilities of drainage at that level.