Endoderm is the innermost of the three primary germ layer
s in the very early embryo
. The other two layers are the ectoderm
(outside layer) and mesoderm
(middle layer), with the endoderm being the innermost layer. Cells migrating inward along the archenteron
form the inner layer of the gastrula
, which develops into the endoderm.
The endoderm consists at first of flattened cells, which subsequently become columnar. It forms the epithelial
lining of multiple systems.
In plant biology
, endoderm corresponds to the innermost part of the cortex
) in young shoots
and young root
s often consisting of a single cell
layer. As the plant
becomes older, more endoderm will lignify
The following chart shows the tissue
s produced by the endoderm.
The embryonic endoderm develops into the interior linings of two tubes in the body, the digestive and respiratory tube.
cells are believed to derive from a common precursor.
In humans, the endoderm can differentiate into distinguishable organs after 5 weeks of embryonic development
File:Gray21.png|Section through the embryo.
File:Gray32.png|Section through ovum imbedded in the uterine decidua
Transcription factor network in endoderm induction..jpg|Signaling pathway to inducing endoderm
*Endodermal sinus tumor
*List of human cell types derived from the germ layers