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The Endowment for Human Development
The Endowment for Human Development
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The Body Plan Emerges

4 weeks

From The Biology of Prenatal Development.Buy Now

Label Key:

1. midbrain
2. forebrain
3. umbilical cord
4. hindbrain
5. neck
6. heart
7. left upper limb bud
All ages referenced to fertilization, not last menstrual period.
Four-Week Embryo
Four-Week Embryo
Digestive Tract, 4-Week Embryo
Digestive Tract, 4-Week Embryo
The Body Plan Emerges
The Body Plan Emerges
Right Upper Limb
Right Upper Limb
The Heart in Motion
The Heart in Motion
Central Nervous System
Central Nervous System
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