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
Help give babies a healthy start and a healthy future. Donate now.