Veins in the extremities carry blood to the heart and lungs, where the blood is oxygenated. As the blood returns to the heart from the lungs, the arteries carry the oxygen-rich blood out to the body.
Update Date 2/7/2016
Updated by: Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.