Dr Khaldoun Khamaiseh FRCOG MRCP

Consultant in Obstetrics & Gynecology & reproductive medicine

Fertilization occure in the ampulla of the fallopian tube

Then division into morula while in the fallopiam tube

Then blastocyst moves into uerus and impalnts: embedding into the decidua to get blood supply and nutrition

The inner cell mass differentiates and forms outer(ectodermal layer) and inner (endodermal layer), between them the mesodermal layer

Two small cavities appear one in the ectoderm forms amniotic sac

And one in the endoderm forms Yolk sac

The two small spheres covered by mesoderm, move into the middle of the blastocyst cavity , the mesoderm form the connecting stalk with future umbilical cord

The 2 opposing layers of ectoderm and endoderm with the mesoderm in between form the actual embryo

Expansion of the amniotic sac takes place and the yolk sac disappears

Within the embryo the vessels in the cephalic end differentiates to form the heart followed by fetal blood cells formation

Ectoderm: skin, hair, Nervous system,pituitary gland, salivary glands

Endoderm: Gastrointestinal tract, Liver, pancreas , respiratory tract , germ cells

Mesoderm: Bone muscle cartilage, cardiovasular system, connective tissue, genital tract

Differentiation

Complete formation