The lacerum segment, or C3, is a short segment that begins above the foramen lacerum and ends at the petrolingual ligament, a reflection of periosteum between the lingula and petrous apex (or petrosal process) of the sphenoid bone. The lacerum portion is still considered 'extra-dural', as it is surrounded by periosteum and fibrocartilage along its course. The vidian artery arises from the lacerum segment, though it is often too small to be angioraphically visible. It is erroneously stated in several anatomy text books that the internal carotid artery passes through the foramen lacerum. This at best has only ever been a partial truth in that it passes through the superior part of the foramen on its way to the cavernous sinus. As such it does not traverse the skull through it. The inferior part of the foramen is actually filled with fibrocartilage. The broad consensus is that the internal carotid artery should not be described as travelling through the foramen lacerum.