ANATOMY & PHYSIOLOGY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site atrium Either of the two (right and left) upper chambers of the four-chambered heart. The left atrium receives oxygenated blood from the pulmonary veins; the right atrium receives deoxygenated blood from the venae cavae. The atria are comparatively thin-walled since they only pump blood down into the muscular ventricles. The term is also used for various other chambers in animals. Related entry    • atrial septal defect Related category    • ANATOMY AND PHYSIOLOGY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP