左さ房ぼうMeanings1nounleft atriumanatomyMedical term for the left upper chamber of the heart. Used in anatomy and clinical contexts.左さ房ぼうは肺はいから酸さん素そを多おおく含ふくむ血けつ液えきを受うけ取とる。The left atrium receives oxygen-rich blood from the lungs.