HealthJuly 20, 2026
ectoderm
ˈɛktəˌdɜrm
Definition
The outermost layer of an embryo in early development, which gives rise to both the skin and the nervous system.
Etymology
Derived from the Greek words 'ektos' (outside) and 'derma' (skin). It was coined in the 19th century by biologists to describe the primary germ layer that forms the outer covering and neural structures of an organism.
In the news
The article uses this term to explain that because the skin and brain originate from the same embryonic tissue, they remain physically and biologically interconnected throughout a person's life.
How eczema and acne can affect your mental health
Read the full article ↗National Geographic