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The Endowment for Human Development
The Endowment for Human Development
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Upper and Lower Limb Buds

4 weeks, 6 days

From The Biology of Prenatal Development.Buy Now

Note:

The limb buds first appear around 4 weeks after fertilization. These humble buds will give rise to complete fingers and toes, elbows and knees, and arms and legs—all in the next three to four weeks!

Label Key:

1. right upper limb
2. spine
3. right lower limb bud with marginal vein
4. tip of lower spine (caudal eminence)
5. umbilical vein within umbilical cord
All ages referenced to fertilization, not last menstrual period.
Heart and Liver
Heart and Liver
Head and Neck
Head and Neck
Upper and Lower Limb Buds
Upper and Lower Limb Buds
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Head and Heart
Upper and Lower Limb Buds
Upper and Lower Limb Buds
The Lower Embryo
The Lower Embryo
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