Skip Navigation
The Endowment for Human Development
The Endowment for Human Development
Improving lifelong health one pregnancy at a time.
Donate Now Get Free Videos

Image Gallery

3-Week Embryo

3 weeks

From The Biology of Prenatal Development.Buy Now

Label Key:

1. amnion
2. amniotic cavity
3. umbilical cord
4. allantois
5. yolk sac
All ages referenced to fertilization, not last menstrual period.
Left Lateral View: 3-Week Embryo
Left Lateral View: 3-Week Embryo
Three-Week Embryo
Three-Week Embryo
3-Week Embryo
3-Week Embryo
The Folding of the Embryo
The Folding of the Embryo
The 4-Week Embryo
The 4-Week Embryo
The Folding Heart
The Folding Heart
Help give babies a healthy start and a healthy future. Donate now.
Free resources and training for educators