Right posterolateral view of the middle meningeal artery arborization within the cranial dura. The middle meningeal artery, the largest of the paired meningeal arteries, is the principal blood supply to the meninges and calvaria. Posteriorly, within the attachment of the tentorium cerebelli, is the transverse sinus, which continues as the sigmoid sinus at the petrooccipital angle. Near this angle the transverse sinus receives the superior petrosal sinus draining blood from the cavernous sinus. The superior petrosal sinus is located along the attachment of the tentorium cerebelli to the superior border of the petrous portion of the temporal bone. (Image courtesy of AL Rhoton, Jr.)