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: Clinical Highlights

Yolk Sac and Vitelline Vessels

#82, Slide 42 of 58

5 weeks, 6 days

From The Biology of Prenatal Development.Buy Now

Note:

According to some experts, the preferred name for "yolk sac" is "umbilical vesicle."

Label Key:

1. vitelline vessels
2. yolk sac
All ages referenced to fertilization, not last menstrual period.
Tell your story. Create your own pregnancy calendar.
Help give babies a healthy start and a healthy future. Donate now.