nounmass nounEmbryology Zoology
The innermost layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the lining of the gut and associated structures.
- ‘In addition, they act as messengers, bearing molecular orders to the mesoderm and endoderm which they contact on arrival.’
- ‘In this tissue, therefore, the fate of some of the cells has been changed from prospective gut endoderm to mesoderm and ectoderm.’
- ‘Other asymmetric anatomical features - such as placement of the heart and liver - are products of different layers, the mesoderm and endoderm.’
- ‘These cells, usually seen as being mesodermal, apparently represent another cell line originating from endoderm.’
- ‘At a tissue level, an adult hydra is essentially a tube composed of two tissue layers, the ectoderm and the endoderm, which extend throughout the animal.’
Mid 19th century: from endo- ‘within’ + Greek derma ‘skin’.
We take a look at several popular, though confusing, punctuation marks.