part of part of connecting branch of anterior cerebral artery circle of Willis systemic artery communicating artery anterior communicating artery Wikipedia:Anterior_communicating_artery EMAPA:18599 SCTID:181311009 UBERON:0006764 A blood vessel of the brain that connects the left and right anterior cerebral arteries. The anterior communicating artery connects the two anterior cerebral arteries across the commencement of the longitudinal fissure. Sometimes this vessel is wanting, the two arteries joining together to form a single trunk, which afterward divides; or it may be wholly, or partially, divided into two. Its length averages about 4 mm, but varies greatly. It gives off some of the anteromedial ganglionic vessels, but these are principally derived from the anterior cerebral artery. It is part of the cerebral arterial circle, also known as the circle of Willis. FMA:50169 NCIT:C32087 EHDAA2:0000586 branch of anterior cerebral artery