The occipital vein
begins in a plexus
at the back part of the vertex
of the skull
From the plexus emerges a single vessel, which pierces the cranial attachment of the Trapezius and, dipping into the suboccipital triangle, joins the deep cervical and vertebral veins.
Occasionally it follows the course of the occipital artery and ends in the internal jugular; in other instances, it joins the posterior auricular vein and through it opens into the external jugular.
The parietal emissary vein connects it with the superior sagittal sinus; and as it passes across the mastoid portion of the temporal bone, it receives the mastoid emissary vein which connects it with the transverse sinus.
The occipital diploic vein sometimes joins it.