Anterior inferior endoscopic view of pituitary gland and internal carotid arteries. The pituitary gland is in view in the lower center of the image. Its stalk or infundibulum extends superiorly to the hypothalamus and is bordered in front by the optic chiasm and laterally by the optic tracts. The gland is bounded laterally by the internal carotid arteries. The lacerum or C3 segment of the ICA continues from the petrous or C2 segment after this emerges from the carotid canal intracranially. It is a short segment that begins superior to the foramen lacerum and ends at the petrolingual ligament where it continues as the cavernous or C4 segment of artery. This periosteal ligament extends between the lingula of the sphenoid bone and petrous apex of temporal bone. The petrolingual ligament marks the posteroinferior attachment of the lateral wall of the cavernous sinus. Associated with the inferior surface of the frontal lobes are the olfactory tracts conveying olfactory information from the nasal epithelium to the olfactory cortex and the anterior cerebral arteries, which are connected by the short anterior communicating artery.  The optic nerves radiate laterally with the ophthalmic arteries into the optic canals. Along the lateral wall of the cavernous sinus can be seen the oculomotor and ophthalmic nerves. The abducens nerve courses within the sinus along the lateral surface of the cavernous ICA. All three nerves enter the orbit via the superior orbital fissure.  (Image courtesy of PA Rubino)