Posterior Communicating Artery
The structure indicated is the posterior communicating artery of the circle of Willis.
It is one of the blood vessels which contributes to the arterial Circle of Willis – an anastomosis of arterial vessels located on the base of the brain, consisting of the following arteries:
- Anterior cerebral artery
- Anterior communicating artery
- Internal carotid artery
- Posterior cerebral artery
- Posterior communicating artery
The posterior communicating artery connects the three cerebral arteries on the same side. It connects to the terminal part of the internal carotid artery before it bifurcates into the anterior cerebral artery and the middle cerebral artery. Posteriorly, it connects to the posterior cerebral artery. The posterior communicating artery is important because it connects the anterior circulation to the posterior circulation - providing a point of “communication” between the two systems.
This vessel is a fairly common site for the formation of aneurysms (third most common site within the Circle of Willis, the most common being the anterior communicating artery).
Learn more about the Circle of Willis in this tutorial!