Yolk sac and Allantois Respiratory a Yolk sac Heart Liver bud Primitive Gut Duodenum Vitellin >3rd week, Germ Cells >3rd to 6th week membrane Blood island Allantois sto. Chsd Develmmaet Be Cepyighdo tw Meoraw-hsa cemen的A构eed The placenta and the Caudal extension of Umbilical cord hindgut Allantoic a pairs Uterus Umbilical Allantoic V pairs cord Umbilic allantois Umbili cord Umbilical Umbilical vessels n Fetal portion Maternal of placenta portion of 2A+1V acenYolk sac and Allantois ▪ Yolk sac ➢ Primitive Gut ➢ 3 rd week, Germ Cells ➢ 3 rd to 6th week, Blood island ▪ Allantois ➢ Caudal extension of hindgut ➢ Allantoic A pairs ➢ Allantoic V pairs Umbilical vessels 2A+1V