The cerebrum of the brain is supplied by three main cerebral arteries:
Both the ACA and MCA originate from the cerebral portion of internal carotid artery, while PCA branches from the intersection of the posterior communicating artery and the anterior portion of the basilar artery. The three cererbal arteries are linked via the anterior communicating artery and the posterior communicating arteries. All three arteries give branches that perforate brain the medial central portions prior to branching and bifurcating further.
The arteries are usually divided into different segments from 1-4 or 5 to denote how far the level of the branch with the lower numbers denoting vessels closer to the source artery. Even though the arteries branching off these vessels retain some aspect of constancy in terms of size and position, a great amount of variety in topography, position, source and prominence nevertheless exists.
This article uses material from the Wikipedia article Cerebral arteries, which is released under the Creative Commons Attribution-Share-Alike License 3.0