内ない中ちゅう胚はい葉よう

Meanings

1

endomesoderm

A technical term in embryology referring to the common precursor tissue that gives rise to both endoderm and mesoderm.

内ない胚はい葉よう
Refers specifically to the endoderm, one of the germ layers derived from the endomesoderm.
中ちゅう胚はい葉よう
Refers specifically to the mesoderm, the other germ layer derived from the endomesoderm.

Compound of 内 (endo-), 中 (meso-), and 胚葉 (germ layer). The term is a direct calque of the English 'endomesoderm'.