Endoderm refers to the inner layer of the embryo which becomes the lungs and the digestive system inner layer of the embryo from which the lungs and digestive system develop.

"endoderm" is not a concept in the field of psychology. Endoderm is one of the three primary germ layers that form during embryonic development, which gives rise to the epithelial linings and glands of the respiratory and digestive tracts, as well as other internal organs. It is a concept studied in the field of developmental biology.