[SOUND] In this module, we'll be discussing the vascular anatomy of the human brain. The brain consumes a tremendous amount of energy and oxygen, which is supplied by a highly intricate system of arteries and veins. On the bottom left-hand side, you can see an angiogram of the blood supply to the head and the brain. In the middle, you can see an example of the complexity of the innervation of the blood supply to the brain. And similarly on the right. In the right image, at the top, would be the cortical surface. And as you move down towards the center of the brain, you'll see more and more refined and detail arteries and veins that supply blood to the neurons and glia in that area. The blood is supplied through the internal carotid artery which originates from the aorta. Initially, it forms the common carotid artery which then splits off into the external carotid artery, which supplies blood to the face and skull, and the internal carotid artery, which forms the main blood supply to the brain. From the internal carotid arteries, highlighted with the arrows in this image, blood enters the Circle of Willis. From the Circle of Willis, the blood gets distributed through a series of arteries and veins that each supply blood to specific brain areas. In the middle here, you can see an actual photograph of the Circle of Willis and the arteries and veins entering the bottom of the brain. From the Circle of Willis, blood gets distributed to the anterior cerebral artery, the middle cerebral artery, the posterior cerebral artery, the superior cerebellar artery, the pontine arteries, the anterior inferior cerebellar artery, the vertebral artery, and the posterior inferior cerebellar artery. This highly organized system of blood vessels provides a very specific and organized blood supply to the different areas of the brain. In fact, it is possible to create cortical vascular territories, or areas of the brain, that are supplied in blood from these specific individual arteries. And you will see that these boundaries are fairly specific and there's a little overlap. This is important for neuro-imaging methods methods that we will discuss down the line, that blood is supplied from the specific origin and innervates specific delineated areas of the cortex. [SOUND]