This exhibit depicts the blood supply of the cerebrum laterally, sagittally, and inferiorly. Each brain is color coded to delineate the territories of the anterior (green), middle (yellow), and posterior (blue) cerebral arteries. An enlargement of the Circle of Willis demonstrates the anastomoses of the three cerebral arteries, internal carotid arteries, and the basilar artery. An aneurysm can be seen projecting anteriorly from the anterior communicating artery in the Circle of Willis. Options for aneurysm treatment are depicted to the right. The first option shows the surgical placement of a clip on the neck of the aneurysm. The second option includes the insertion of platinum wire into the aneurysm until it is filled with coils.