II. Anatomy: Posterior Circulation
- Bilateral Vertebral Arteries
- Bilateral subclavian arteries (arising from aortic arch) branch into the bilateral Vertebral arteries
- Vertebral arteries ascend each side of the Cervical Vertebrae (via their bilateral transverse foramina)
- Vertebral arteries provide branch to Anterior Spinal Artery, and to the posterior inferior Cerebellum artery (PICA)
- Vertebral arteries combine to form Basilar Artery at level of Medulla
- Basilar Artery
- Basilar Artery branches to Cerebellum (AICA, SCA) and Brainstem
- Basilar Artery divides to form bilateral posterior cerebral arteries
- Posterior Cerebral Arteries
- Each Posterior Cerebral Artery connects to the ipsilateral Anterior Circulation via the posterior communicating arteries
- Function
- Posterior Circulaion supplies Occipital Lobe, inferior Temporal Lobe, Brain Stem and Cerebellum
III. Pathophysiology: Cerebrovascular Accident
- Vertebrobasilar obstruction may result in Vision Loss, Vertigo or Brain Stem effects
- See Vertebrobasilar CVA
- See Posterior Cerebral Artery CVA
- See Posterior Inferior Cerebellar Artery CVA
- Basilar Artery obstruction near the Vertebral Artery junction (before giving rise to the posterior cerebral arteries)
- Results in complete cortical blindness (bilateral Occipital Lobe infarcts)
- Basilar Artery obstruction in pons (Locked-In Syndrome)
- Complete motor paralysis except preserved diaphragmatic breathing and vertical eye movements
- Neurologic function otherwise intact (Awake, alert and lucid with intact cognitive function, and intact Sensation)
- Cerebellar artery obstruction
- Affects Cerebellum and Brain Stem
- Vertebral Artery obstruction
- May lack physical findings due to collateral circulation
- Posterior Cerebral Artery Aneurysm (1% of Cerebral Aneurysms)
- Cranial Nerve 3 (Oculomotor Nerve) passes between Superior Cerebellar Artery and Posterior Cerebral Artery
- Compression of Cranial Nerve 3 may result in Mydriasis and Cranial Nerve 3 Extraocular Movement deficit
IV. References
- Gilman (1989) Manter and Gatz Essentials of Neuroanatomy and Neurophysiology, Davis, p. 216-21
- Goldberg (2014) Clinical Neuroanatomy, Medmaster, p. 6-15
- Netter (1997) Atlas Human Anatomy, ICON Learning, p. 130-9
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| Definition (NCI) | An artery formed by the union of the two vertebral arteries at the posterior border of the pons then diverges at the anterior border forming the two superior and two posterior cerebral arteries. |
| Definition (MSH) | The artery formed by the union of the right and left vertebral arteries; it runs from the lower to the upper border of the pons, where it bifurcates into the two posterior cerebral arteries. |
| Concepts | Body Part, Organ, or Organ Component (T023) |
| MSH | D001488 |
| SnomedCT | 59011009 |
| English | Arteries, Basilar, Artery, Basilar, Basilar Arteries, Basilar Artery, BA - Basilar artery, Arteria basilaris, arteries basilar, basilar arteries, basilar artery, artery basilar, Basilar artery, Structure of basilar artery (body structure), Structure of basilar artery, Basilar artery, NOS, BA |
| Swedish | Basilarartär |
| Czech | arteria basilaris |
| Finnish | Kallonpohjavaltimo |
| Russian | BAZILIARNAIA ARTERIIA, БАЗИЛЯРНАЯ АРТЕРИЯ |
| Croatian | BAZILARNA ARTERIJA |
| Polish | Tętnica podstawna |
| Norwegian | Arteria basilaris, Basilarisarterien |
| Spanish | arteria basilar, estructura de la arteria basilar (estructura corporal), estructura de la arteria basilar, Arteria Basilar |
| German | Arteria basilaris, Schädelbasisarterie |
| Italian | Arteria basilare |
| Dutch | Arteria basilaris |
| Portuguese | Artéria Basilar |
| French | Tronc basilaire, Artère basilaire |
Ontology: Structure of vertebral artery (C0042559)
| Definition (NCI) | The first branch of the subclavian artery that ascends both sides of the neck and merges at the middle line to from the basilar artery at the level of the pons. |
| Definition (MSH) | The first branch of the SUBCLAVIAN ARTERY with distribution to muscles of the NECK; VERTEBRAE; SPINAL CORD; CEREBELLUM; and interior of the CEREBRUM. |
| Concepts | Body Part, Organ, or Organ Component (T023) |
| MSH | D014711 |
| SnomedCT | 85234005 |
| English | Arteries, Vertebral, Artery, Vertebral, Vertebral Artery, VA - Vertebral artery, Vertebral Arteries, Arteria vertebralis, arteries vertebral, vertebral arteries, artery vertebral, vertebral artery, Vertebral artery, Structure of vertebral artery (body structure), Structure of vertebral artery, Vertebral artery, NOS, VA |
| Swedish | Kotartär |
| Czech | arteria vertebralis, vertebrální artérie |
| Finnish | Nikamavaltimo |
| French | Artères vertébrales, Artère vertébrale |
| Italian | Arterie vertebrali, Arteria vertebrale |
| Russian | VERTEBRAL'NAIA ARTERIIA, POZVONOCHNAIA ARTERIIA, ВЕРТЕБРАЛЬНАЯ АРТЕРИЯ, ПОЗВОНОЧНАЯ АРТЕРИЯ |
| Japanese | 椎骨動脈 |
| Croatian | VERTEBRALNA ARTERIJA |
| Polish | Tętnica kręgowa |
| Spanish | estructura de arteria vertebral (estructura corporal), estructura de arteria vertebral, estructura de la arteria vertebral (estructura corporal), estructura de la arteria vertebral, arteria vertebral, Arteria Vertebral |
| Norwegian | Vertebralarterie, Arteria vertebralis, Virvelarterie |
| German | Arteria vertebralis |
| Dutch | Arteria vertebralis |
| Portuguese | Artéria Vertebral |
Ontology: Posterior Circulation Intracranial Artery (C1514258)
| Definition (NCI) | Any of the arteries that are part of the intracranial posterior circulation. |
| Concepts | Body Part, Organ, or Organ Component (T023) |
| English | Posterior Circulation Intracranial Artery |
