Superior oblique view of right middle fossa and tentorial incisura. The frontal and temporal lobes have been reflected upward to expose structures related to the optic canals and tentorial notch. The optic nerves emerge from the optic canals, unite at the optic chiasm, and vision information is transmitted to the vision cortex via the optic tracts. The intradural portion of the internal carotid artery is in view. Also, the basilar artery ascends on the pons and gives rise to the superior cerebellar and terminal posterior cerebral arteries. Emerging between these from the midbrain is the oculomotor nerve that pierces the dura along the roof of the cavernous sinus. Entering the lateral wall of the cavernous sinus inferior to the oculomotor nerve is the trochlear nerve. (Image courtesy of PA Rubino)