Amnion of mammalian embryo is derived from ectoderm and mesoderm. It is one of the extraembryonic membrane which is formed by the amniogenic cells of ectodermal
origin on inner side and somatopleuric extraembryonic mesoderm on outer side. This membrane acts as a shock absorber for the foetus, regulates foetal body temperature and prevents desiccation.
The origin of other extraembryonic membranes is as follows
Chorion Trophoetoderm and mesoderm.
Allantols and Yolk sac Outer mesoderm and inner endoderm.
