Posterior Communicating Artery
The two posterior communicating arteries form the posterolateral borders of the circle of Willis, connecting posteriorly to the posterior cerebral arteries and anteriorly to the internal carotid arteries on each side. As such, it forms a connection between the anterior and posterior cerebral circulations, which make it particularly important for the development of collateral circulation when one part of the blood supply is compromised. The posterior communicating arteries supply the thalamus, hypothalamus, and optic chiasm that carries visual signals. It is the second most common location for cerebral aneurysms. Ruptures of these aneurysms can result in cranial nerve palsies, especially oculomotor dysfunction.