Posterior communicating artery

Overview
In human anatomy, the posterior communicating artery is a one of a pair of right-sided and left-sided blood vessels in the circle of Willis. It connects the three cerebral arteries of the same side. Anteriorly, it is one portion of the terminal trifurcation of the internal carotid artery. The anterior cerebral artery and the middle cerebral artery are the other two branches of the trifurcation. Posteriorly, it communicates with the posterior cerebral artery.

Pathology
Aneurysms of the posterior communicating artery are the second most common circle of Willis aneurysm (the most common are anterior communicating artery aneurysms) and can lead to oculomotor nerve palsy.