part of part of in lateral side of connecting branch of system internal carotid artery posterior communicating artery EHDAA:3352 TAO:0005001 PCA EHDAA2:0004518 FMA:50084 Wikipedia:Posterior_communicating_artery SCTID:181314001 PCS NCIT:C33357 ZFA:0005001 RETIRED_EHDAA2:0001487 One of a pair of right-sided and left-sided blood vessels in the circle of Willis. It connects the three cerebral arteries of the same side. Anteriorly, it is one portion of the terminal trifurcation of the internal carotid artery. The anterior cerebral artery and the middle cerebral artery are the other two branches of the trifurcation. Posteriorly, it communicates with the posterior cerebral artery. posterior communicating segment of the basilar artery UBERON:0001628 MA:0002023 EMAPA:18600 caudal communicating segment circle of Willis systemic artery communicating artery lateral structure