The embryo is at Carnegie Stage 6 . The amnion is a small cap on the ectodermal surface of the embryonic disk. The embryo attaches to the trophoblast shell by way of the connecting stalk. The embryo has developed from the embryonic disk. It has cranial and caudal regions and a beating heart tube.
Blood vessels connect to the placenta.
The 3 umbilical vessels are in the connecting stalk. The amnion is growing, and the yolk sac is becoming smaller. The size of the junction of the amnion and ectoderm is becoming smaller as the body wall is closing.