Posterior communicating artery

Dr Tom Foster and Dr Jeremy Jones et al.

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

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

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

Perforators from the PCOM supply:

Anatomy: Brain

Anatomy: Brain

Article information

rID: 5937
Section: Anatomy
Synonyms or Alternate Spellings:
  • Posterior communicating artery (PCOM)
  • PCOM
  • P Comm
  • Posterior communicating arteries
  • PCOMs

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1: circle of Willis diagram showing P Comm
    Drag here to reorder.
  • Figure 2: normal COW anatomy
    Drag here to reorder.
  • Case 1: bilateral fetal posterior communicating arteries
    Drag here to reorder.
  • Case 2: PCOM infundibulum
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.