posterior communicating artery

The posterior communicating artery (PCOM or P Comm) makes up the posterior linkage in the circle of Willis.

Gross anatomy

Course

The PCOM originates from the posterior aspect of the C7 (communicating) segment of the internal carotid artery and extends posteriormedially to anastomose with the ipsilateral posterior cerebral artery and form part of the circle of Willis.

Branches

The PCOM gives off many fine, scarcely visible, perforating branches. The largest perforating branch is called the premamillary (or anterior thalamoperforating) artery.

Vascular territory

Perforators from the PCOM supply:

Variant anatomy