1 — Accessory nerve [XI]; 2 — Vagus nerve [X]; 3 — Glossopharyngeal nerve [IX]; 4 — Hemisphere of cerebellum [H II — H X]; 5 — Anterior inferior cerebellar artery; 6 — Choroid plexus of fourth ventricle; 7 — Vestibulocochlear nerve [VIII]; 8 — Facial nerve [VII]; 9 — Labyrinthine artery; 10 — Trigeminal nerve [V]; 11 — Superior cerebellar artery; 12 — Posterior cerebral artery, postcommunicating part; P2 segment; 13 — Oculomotor nerve [III]; 14 — Posterior communicating artery; 15 — Internal carotid artery; 16 — Optic nerve [II]; 17 — Optic chiasm; Optic chiasma; 18 — Olfactory tract; 19 — Medial frontobasal artery; Medial orbitofrontal artery; 20 — Anterior cerebral artery, precommunicating part; Al segment; 21 — Anterior communicating artery; 22 — Olfactory bulb; 23 — Subcallosal area; Subcallosal gyrus; 24 — Lateral frontobasal artery; Lateral orbitofrontal artery; 25 — Middle cerebral artery, sphenoid part; horizontal part; M1 segment; 26 — Insula; Insular lobe; 27 — Middle cerebral artery, insular part; M2 segment; 28 — Anterior choroidal artery; 29 — Temporal lobe; 30 — Posterior cerebral artery, precommunicating part; P1 segment; 31 — Posterior perforated substance; 32 — Basilar artery; 33 — Hypoglossal nerve [XII]; 34 — Abducent nerve; Abducens nerve [VI]; 35 — Vertebral artery; 36 — Posterior inferior cerebellar artery; 37 — Anterior spinal
artery; 38 — Spinal cord