The amniotic sac, commonly called the bag of waters, sometimes the membranes, is the sac in which the embryo and later fetus develops in amniotes. It is a thin but tough transparent pair of membranes ...

Viewer discretion is advised. A video from a Spanish hospital captures the moment a baby is born within the amniotic sac, an occurrence that only happens 1 in every 80,000 births. It is also known ...

Yolk sac is then infiltrated with a system of blood vessels, carrying nutrients from the yolk back to the embryo. Other extra-embryonic folds expand up over the embryo to form the amniotic folds. The ...

Yolk sac is then infiltrated with a system of blood vessels, carrying nutrients from the yolk back to the embryo. Other extra-embryonic folds expand up over the embryo to form the amniotic folds. The ...