Wiktionary
n. One of the chambers of the heart in humans and other mammals, receives oxygenated blood from the lungs via the pulmonary veins, and pumps it into the left ventricle.
WordNet
n. the left upper chamber of the heart that receives blood from the pulmonary veins [syn: left atrium of the heart, atrium sinistrum]
Usage examples of "left atrium".
The map had routed him out of this pressed tunnel through the inferior vena cava to the right atrium and thence through the right ventricle, the pulmonary arteries, through the valves, to the lungs, the pulmonary veins, crossover to the left side of the heart (left atrium, left ventricle), the aorta--bypassing the three coronary arteries above the aortic valves--and down over the arch of the aorta--bypassing the carotid and other arteries--to the celiac trunk, where the arteries split in a confusing array: the gastroduodenal to the stomach, the hepatic to the liver, the splenic to the spleen.
Pre-oxygenated ersatz blood was being fed into his heart's left atrium, in lieu of a supply from the lungs, pumped through the body once only, then removed via the pulmonary arteries and discarded.