2-Minute Neuroscience: Blood Supply of the Brain

In this video I discuss the major arteries that supply the brain, starting with the internal carotid and vertebral arteries and covering many of the major vessels of the brain. TRANSCRIPT: Welcome to 2 minute neuroscience, where I explain neuroscience topics in 2 minutes or less. In this installment I will discuss the blood supply of the brain. The internal carotid arteries supply the brain with about 80% of its blood, while the vertebral arteries contribute the remaining 20%. After ascending to the brain, the internal carotid arteries split into the anterior and middle cerebral arteries. The anterior cerebral arteries supply the medial frontal and parietal lobes, and they are connected by the anterior communicating artery. The middle cerebral arteries supply most of the lateral surface of the cerebral hemispheres. Before splitting into the middle and anterior cerebral arteries, the internal carotids give rise to the anterior choroidal arteries, which supply a number of different structures, and the posterior communicating arteries, which connect the internal carotid arteries to the posterior cerebral arteries. The vertebral arteries give rise to the posterior inferior cerebellar arteries, which supply the inferior surface of the cerebellum and in most brains will also give rise to the posterior spinal arteries, which supply the posterior spinal cord. The anterior spinal artery, which supplies the anterior spinal cord, also branches off the vertebral arteries, then the two vertebral arteries come together to form the basilar artery. The basilar artery gives rise to the anterior inferior and superior cerebellar arteries, which supply the rest of the cerebellar surface. Then, at the the level of the midbrain, the basilar artery splits into two posterior cerebral arteries. The posterior cerebral arteries supply the medial and inferior surfaces of the occipital and temporal lobes. The anterior cerebral, internal carotid, and posterior cerebral arteries of both sides of the brain are all connected, forming what is known as the Circle of Willis. This interconnection can allow blood flow to continue if a major vessel is blocked on one side of the brain. Reference: Vanderah TW, Gould DJ. Nolte’s The Human Brain. 7th ed. Philadelphia, PA: Elsevier; 2016.