Corpus: Posterior inferior cerebellar artery

The posterior inferior cerebellar artery, or PICA for short, is the largest branch of the vertebral artery and one of the three main arteries supplying the cerebellum.

The PICA originates from the vertebral artery, winding around the upper portion of the medulla oblongata and passing through the cerebellopontine angle. It may form a vascular loop near the internal acoustic meatus. The artery then travels between the origins of the vagus nerve and the accessory nerve and terminates on the caudal surface of the cerebellum, where it divides into two branches.

The PICA supplies arterial blood to parts of the medulla oblongata, the caudal regions of the cerebellum, and the choroid plexus of the fourth ventricle.

A vascular loop in the porus acusticus internus can result in "vascular loop syndrome," which may affect cranial nerve function. Occlusion of the PICA can lead to a PICA infarction, resulting in ischemic damage to the areas it supplies.