Medicine & BodyGreek → English
Ectoderm
/ˈɛktə(ʊ)dəːm/noun
The outermost of the three germ layers of an early embryo, which gives rise to skin, hair and the nervous system.
The Greek roots
ἐκτός
ektós
outside
δέρμα
dérma
skin
Literally: “outer skin”
The story of the word
The name only covers half of what the layer does. Skin is the obvious product, but the same sheet folds inward to form the entire brain and spinal cord, so the nervous system is technically modified skin. Nineteenth-century embryologists named the three layers by position, ectoderm outside, mesoderm between, endoderm within, and the naming has outlived several theories about what they mean.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 19th century
Same family
endodermmesodermdermatologyhypodermicectopic
In a sentence
Both the epidermis and the neural tube come from ectoderm.
Damage at this stage affects every ectoderm derivative at once.