Tim Taylor is a senior writer at Innerbody Research focusing on human anatomy and physiology. Tim earned both his Bachelor of Science degree in Biology and his Master's degree in Teaching from the University of Pittsburgh.

Last updated: Jan 31st, 2025

Click to View Larger Image

The yolk sac is established during the second week of embryonic development and although it has no nutritive value, it is essential for the growth of the embryo. The umbilical cord forms as the yolk sac shrinks and usually attaches near the center of the placenta.

No spam! Your privacy is important to us.

Fitness & Diet Hair & Skin Mental Health Wellness Research Human Body

About Us Editorial Policy Ad Policy Privacy Policy Terms of Use Do Not Sell My Info

Innerbody Research does not provide medical advice, diagnosis, or treatment. You must consult your own medical professional.