Arterial Supply of the Lateral Surface of the Central Lobe. A–E, Arterial supply of the lateral surface of the central lobe: posterior internal frontal artery (dark blue), paracentral artery (orange), superior parietal artery (light blue), precentral artery (green), central artery (red), and anterior parietal artery (yellow). A, Most common pattern. The posterior interior frontal and paracentral branches of the ACA supply the upper part. The majority of the lateral surface is supplied by the central branch of the MCA. The areas not supplied by the central artery are the anterior inferior part of the precentral gyrus supplied by the precentral and the posterior edge of the postcentral gyrus supplied by the anterior parietal artery. These cortical arteries often course in the sulci as well as on the surface of the gyri. B–E, Frequently encountered variations. B, The lower two-thirds of the central lobe is predominantly supplied by the central artery. On the superior third, the precentral gyrus is supplied by the posterior interior frontal artery and the postcentral gyrus by the superior parietal artery. C, The superior parts of the precentral and postcentral gyri are supplied by the paracentral and superior parietal arteries, respectively. There is no supply from the posterior inferior frontal artery. A larger than usual area of the precentral gyrus is supplied by the precentral artery. D, The precentral and the anterior parietal arteries have a larger than usual area of supply that narrows the large proximal area usually supplied by the central artery. The superior third is supplied by the posterior internal frontal and paracentral arteries. E, There is no contribution from the precentral artery. The anterior parietal artery supplies the lower two-thirds of the posterior part of the postcentral gyrus. The area supplied by the cortical branches of the ACA is divided between the posterior interior frontal, paracentral, and superior parietal arteries. (Images courtesy of AL Rhoton, Jr.)