Anterior view of cavernous sinus in coronal section. The cavernous venous sinus is located along the lateral walls of the body of the sphenoid between the meningeal and periosteal dural layers. Four cranial nerves travel through the lateral wall of the cavernous sinus. From superior to inferior they are the: oculomotor (CN III), trochlear (CN IV), ophthalmic (CN V1), and maxillary (CN V2) nerves. Structures travelling within the cavernous sinus include the internal carotid artery (ICA) and abducens nerve (CN VI). The sinuses are connected across the midline by intercavernous sinuses. The body of the sphenoid contains the sphenoid sinus. The optic nerve and ophthalmic artery can be seen in the optic canals within the lesser wings of the sphenoid. Superiorly, the frontal lobes are in view with the anterior cerebral arteries in the interhemispheric fissure. The temporal lobes rest in the floor of the middle fossa and the middle cerebral arteries are shown within the lateral fissure. This section includes the proximal portion of the nasopharynx where the pharyngotympanic tubes open into its lateral wall. (Image courtesy of AL Rhoton, Jr.)