This is a left lateral view of a dissection of the head and proximal neck. The mandible has been removed, as has the zygomatic arch, and most of the mastoid process. Note the entrance and exit, respectively, of the internal carotid artery and internal jugular vein from their respective bony openings and a complement of carotid sheath enclosing them. The mastoid segment of the facial nerve is also visible. The sigmoid sinus communicates with the jugular bulb before the latter continues as the internal jugular vein. (Image courtesy of AL Rhoton, Jr.)