Neuroanatomy, Brain Arteries

Excerpt

The brain receives vascular supply from a network of arteries that anastomose to form the circle of Willis. Because the brain has a constant high metabolic demand and no energy supply of its own, it requires a significant blood supply, consuming 15% of total cardiac output; any blockage of blood flow leads to severe damage and a host of neurological pathologies (see Figure. Diagram of the Brain Blood Circulation).

The brain is supplied by the internal carotid arteries (ICAs), which branch from the common carotid arteries, and the vertebral arteries, which branch from the subclavian. The ICA gives rise to the anterior cerebral artery (ACA) and the middle cerebral artery (MCA). The 2 vertebral arteries unite to form the basilar artery, terminating in the 2 posterior cerebral arteries (PCA). The circle of Willis is the combination of these anterior and posterior divisions (see Image. Outer Surface of the Cerebral Hemisphere).