Anterior Cerebral Artery, Gross Anatomy

Description

Arising from the internal carotid artery, the anterior cerebral artery (ACA) courses anteromedially above the optic chiasm toward the longitudinal fissure, then turns superiorly to run along the medial surface of the cerebral hemispheres. Proximal A1 segments travel toward the anterior communicating artery, after which the A2 segment ascends over the rostrum and genu of the corpus callosum and continues as the pericallosal artery, with a callosomarginal branch tracking the cingulate sulcus. Expect the medial frontal and parietal gyri, cingulate gyrus, and superior sagittal region to be oriented as the principal cortical territories, with arteries rendered in red and accompanying venous pathways and dural venous sinuses suggested in blue. Clear midline anatomy. This distribution matters because ACA infarction produces a pattern that clinicians recognize immediately: contralateral leg predominant weakness and sensory loss from involvement of the paracentral lobule, often with abulia or akinetic features when medial frontal circuits are affected. A1 hypoplasia and anterior communicating artery aneurysms sit at the center of collateral flow and subarachnoid hemorrhage discussions, and this overview supports teaching how the circle of Willis compensates when one internal carotid artery is compromised. Use it in neuroanatomy and cerebrovascular modules to map cortical vascular territories on the medial hemisphere, or in stroke education materials to correlate focal deficits with an ACA territory lesion. It also fits neurosurgical and neuroradiology publications explaining anterior communicating artery aneurysm approach planning and the pericallosal course over the corpus callosum. Anatomical accuracy verified by SciePro's Medical Advisory Board.