NCIt definition : An artery formed by the union of the two vertebral arteries at the posterior border
of the pons then diverges at the anterior border forming the two superior and two
posterior cerebral arteries.;
Alternative definition : CDISC: An artery of the brain; in general it arises from the union of the two vertebral
arteries at the posterior border of the pons and branches at the anterior border to
form the two superior and two posterior cerebral arteries.;