1 — External jugular vein; 2 — Vertebral vein; 3 — Deep cervical vein; 4 — Condylar emissary vein; 5 — Mastoid emissary vein; 6 — Sigmoid sinus; 7 — Posterior auricular vein; 8 — Confluence of sinuses; 9 — Occipital vein; 10 — Occipital emissary vein; 11 — Superior petrosal sinus; 12 — Straight sinus; 13 — Superior sagittal sinus; 14 — Parietal emissary vein; 15 — Inferior sagittal sinus; 16 — Basilar vein; 17 — Cavernous sinus; 18 — Frontal vein; 19 — Superior ophthalmic vein; 20 — Angular vein; 21 — Inferior ophthalmic vein; 22 — Venous plexus of foramen ovale; 23 — Pterygoid plexus; 24 — Inferior petrosal sinus; 25 — Retromandibular vein; 26 — Facial vein; 27 — Internal jugular vein