azygos
[az´ĭ-gos] any unpaired part, as the azygos vein.
azygos vein a vein beginning in the abdomen as a continuation of the ascending lumbar vein; it and its tributaries serve as vessels for the return of blood from the thorax to the
superior vena cava. The azygos vein also serves as a connecting link, through the ascending lumbar vein, between the venae cavae returning blood from above and below the heart. See anatomic Table of Veins in the Appendices.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.