Posterior Communicating Artery

Description

Centered on the sella region at the base of the cranial cavity, the posterior communicating artery (arteria communicans posterior) is shown as a short, posteromedially directed channel arising from the supraclinoid internal carotid artery and joining the proximal posterior cerebral artery near the termination of the basilar artery. Anteriorly and medially, the anterior cerebral arteries and anterior communicating artery complete the anterior portion of the Circle of Willis, while laterally the middle cerebral arteries project into the Sylvian fissure region. Surrounding osseous landmarks of the cranial base and its foramina frame the arterial ring. Small vessel caliber changes are apparent. This segment matters because the posterior communicating artery is the hinge between carotid and vertebrobasilar circulation, and its size often determines whether the posterior cerebral artery is “fetal-type” (predominantly internal carotid supply) or basilar-supplied, a detail that changes infarct patterns and angiographic interpretation. Berry aneurysms frequently arise at the internal carotid–posterior communicating junction, a common source of painful third nerve palsy with pupillary involvement due to the nerve’s close relationship to the posterior communicating region. A clean view of the Circle of Willis also supports teaching collateral pathways during carotid stenosis or occlusion. Use this artwork for neuroanatomy and cerebrovascular teaching modules, for neurosurgery or neuroradiology publications discussing the Circle of Willis variants, and for patient-facing diagrams explaining aneurysm location and endovascular coiling targets in the parasellar cistern. It also fits stroke conference slides where vascular territories and collateral routes must be communicated quickly and correctly. Anatomical accuracy verified by SciePro's Medical Advisory Board.