1 — Anterior spinal artery and Vertebral artery, medial branches; paramedian pontine branches; 2 — Basilar artery; 3 — Superior cerebellar artery; 4 — Posterior inferior cerebellar artery; 5 — Anterior inferior cerebellar artery; 6 — Oculomotor nerve [III]; 7 — Cerebral peduncle; 8 — Substantia nigra; 9 — Red nucleus; 10 — Aqueduct of midbrain; Cerebral aqueduct; 11 — Inferior colliculus; 12 — Posterior cerebral artery; 13 — Superior cerebellar artery, peduncular branches; 14 — Posterior communicating artery; 15 — Posterior choroidal artery; 16 — Trigeminal nerve [V]; 17 — Fourth ventricle; 18 — Superior medullary velum; 19 — Superior cerebellar peduncle; 20 — Middle cerebellar peduncle; 21 — Basilar artery, long circumferential branches; 22 — Basilar artery, short circumferential branches; 23 — Basilar artery, Pontine arteries and
medial branches; paramedian pontine branches
