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

Slideshow: Umbilical Cord, Placenta & More

Vitelline Vessels and Yolk Sac

#85, Slide 3 of 35

5 weeks, 2 days

From The Biology of Prenatal Development.Buy Now

Note:

The yolk sac is not enclosed within the amnion.

Label Key:

1. vitelline vessels within yolk stalk
2. yolk sac
All ages referenced to fertilization, not last menstrual period.
Buy the Biology of Prenatal Development DVD
Tell your story. Create your own pregnancy calendar.