yolk sac endoderm

例句：

1. 1. Thedevelopment of the embryo is closely related tothe formation of the yolk sac endoderm.
   胚胎的发展与卵黄囊内皮的形成密切相关。
2. 2. During the earlystages of development, the yolksac endoderm plays a crucialrole in the formation of the neural tube.
   在发育的早期阶段，卵黄囊内皮在形成神经管中起着至关重要的作用。
3. 3. The yolk sacendoderm is responsible for the productionof essential nutrients and hormones that supportthe growth and development of the fetus.
   卵黄囊内皮负责生产支持胎儿生长和发育所必需的重要营养物质和激素。