← Chapter 28
Anatomy & Physiology · Chapter 28
The Germ Layers
Around week 3, the embryo forms
three primary layers
— and every organ in your body traces back to one of them. Tap each layer.
Ectoderm
the trilaminar embryo
The germ layers
outer · middle · inner
The three layers
📷 Reference image
A real labeled figure to compare with the interactive above.
The Germ Layers — OpenStax, CC BY 3.0 (via Wikimedia Commons)