Makindo Medical Notes

Related Subjects: |Cerebral Arterial Perfusion and Clinical Correlates |Anterior circulation Brain |Posterior circulation Brain |Acute Stroke Assessment (ROSIER&NIHSS)

One-third of the cerebral blood supply is from the vertebral arteries.

Vertebral Artery

• First branches of the subclavian arteries on either side, entering the transverse process at C6.
• Ascends through the foramina in the transverse processes of the upper six cervical vertebrae to C1, where they enter the foramen magnum in front of the medulla.
• Inside the skull, the two vertebral arteries join to form the basilar artery.

Branches

• Posterior Inferior Cerebellar Artery (PICA)
  • The largest branch of the vertebral artery, supplying the lateral medulla and lateral cerebellum.
  • Loops around the medulla to reach the inferior surface of the cerebellum.
  • Occlusion can lead to Wallenberg's syndrome (Lateral medullary syndrome).
• Anterior Spinal Artery
  • Supplies the ventral medulla and forms where the vertebral arteries fuse.
• Posterior Spinal Artery: Supplies the dorsal medulla.
• Basilar Artery: Formed at the lower border of the pons by the fusion of the two vertebral arteries.
• Anterior Inferior Cerebellar Artery (AICA): Supplies the lateral pons and anteroinferior cerebellum.
• Superior Cerebellar Artery: Supplies the lateral pons and the superior surface of the cerebellum.
• Pontine Arteries: Approximately 12 small branches that supply the medial pons, coming off at right angles from either side of the basilar artery.
• Internal Auditory Artery: A slender branch that arises near the middle of the basilar artery; it travels with the acoustic nerve through the internal acoustic meatus to supply the internal ear.
• Posterior Cerebral Artery (PCA)
  • Embryologically originates from the internal carotid artery.
  • Passes laterally, joining the posterior communicating artery, then sweeps back around the cerebral peduncle to the occipital lobe.

PCA Branches

• Postero-medial Ganglionic Branches: Arise at the commencement of the PCA, along with branches from the posterior communicating artery, supplying the medial surfaces of the thalami and the walls of the third ventricle.
• Posterior Choroidal Branches: Run forward beneath the splenium of the corpus callosum, supplying the tela choroidea of the third ventricle and the choroid plexus.
• Postero-lateral Ganglionic Branches: Arise after the PCA turns around the cerebral peduncle, supplying portions of the thalamus.
• Anterior Temporal Branch: Supplies the uncus and anterior part of the fusiform gyrus.
• Posterior Temporal Branch: Supplies the inferior temporal gyri, the calcarine sulcus, the cuneus, the lingual gyrus, and the posterior convex surface of the occipital lobe.
• Parietooccipital Branch: Supplies the parietooccipital region.