Posterior Inferior Cerebellar Artery

Written by Azka Mujeeb

Last updated September 15, 2025
8 Revisions

The posterior inferior cerebellar artery (PICA) is an artery of the hindbrain. It is the largest branch of the vertebral artery.

It supplies blood to the inferior cerebellum, medulla oblongata, and parts of the fourth ventricle.

Pro Feature - 3D Model

Course

The posterior inferior cerebellar artery arises from the vertebral artery at the level of the medulla oblongata.

From here, it ascends posteriorly, passing behind the origin of the glossopharyngeal and vagus nerves to reach the inferior border of the pons.

It then curves medially and descends along the margin of the fourth ventricle, before turning laterally into the cerebellomedullary fissure (the space between the cerebellum and medulla).

Within the fissure, the PICA divides into two main terminal branches:

  • Medial branch – courses along the inferior vermis (midline of the cerebellum), supplying the cerebellum and adjacent medullary structures.
  • Lateral branch – extends over the inferior surface of the cerebellar hemisphere, supplying the cerebellar cortex and tonsils.

Fig 1
The origin of the posterior inferior cerebellar artery from the vertebral artery.

Supply

The posterior inferior cerebellar artery supplies the following structures:

  • Dorsolateral medulla
  • Inferior surface of the cerebellum, including the tonsils and vermis
  • Choroid plexus of the fourth ventricle