Definition of Yolk sac

Reviewed on 3/29/2021

Yolk sac: A membrane outside the human embryo that is connected by a tube (the yolk stalk) though the umbilical opening to the embryo's midgut. The yolk sac serves as an early site for the formation of blood and in time, is incorporated into the primitive gut of the embryo


The first sign of pregnancy is most often: See Answer

Health Solutions From Our Sponsors