胚はい膜まく

noun

embryonic membrane; extraembryonic membrane

Technical term in embryology; refers to membranes such as the amnion, chorion, yolk sac, and allantois.

• 胚はい膜まくは発はっ生せいの初しょ期きに形けい成せいされる。

  The embryonic membranes are formed early in development.