The placenta delivers oxygen and nutrients to the growing fetus during pregnancy.

placenta 是医学术语，来自拉丁语，原意为"扁平的蛋糕"，指哺乳动物子宫内连接母体和胎儿的器官。它通过脐带为胎儿提供氧气和营养，同时排出废物。