On the anterior surface of the petrous portion of the temporal bone are seen the eminence caused by the projection of the superior semicircular canal; in front of and a little lateral to this a depression corresponding to the roof of the tympanic cavity; the groove leading to the hiatus of the facial canal, for the transmission of the greater superficial petrosal nerve and the petrosal branch of the middle meningeal artery; beneath it, the smaller groove, for the passage of the lesser superficial petrosal nerve; and, near the apex of the bone, the depression for the semilunar ganglion and the orifice of the carotid canal.
22.
While glymphatic flow was initially believed to be the complete answer to the long-standing question of how the sensitive neural tissue of the CNS functions in the perceived absence of a lymphatic drainage pathway for extracellular proteins, excess fluid, and metabolic waste products, two subsequent articles by Louveau et al . from the University of Virginia School of Medicine and Aspelund et al . from the University of Helsinki reported independently the discovery that the dural sinuses and meningeal arteries are in fact lined with conventional lymphatic vessels, and that this long-elusive vasculature forms the connecting pathway for the entrance and exit of lymphatic fluid and immune cells from the meningeal compartment to the glymphatic system.
