Section 3
Second Week of Development
Book
Version 29
By Boundless
By Boundless
Boundless Anatomy and Physiology
Physiology
by Boundless
6 concepts
![Thumbnail](../../../../../../figures.boundless-cdn.com/31010/square/gray32.jpg)
Trophoblast Development
Trophoblasts are the outer layer of cells that provide nutrients to the embryo and form part of the placenta.
![Thumbnail](../../../../../../figures.boundless-cdn.com/16523/square/gray13.jpg)
Bilaminar Embryonic Disc Development
The floor of the amniotic cavity is formed by the embryonic disc.
![Thumbnail](../../../../../../figures.boundless-cdn.com/31233/square/gray30.jpg)
Amnion Development
The amnion contains the fluid that cushions and protects the fetus.
![Thumbnail](../../../../../../figures.boundless-cdn.com/5376/square/gray22.jpg)
Yolk Sac Development
The yolk sac is vascularized and contributes nutrients to the embryo.
![Thumbnail](../../../../../../figures.boundless-cdn.com/15749/square/gray475.jpg)
Sinusoid Development
The sinusoids are capillaries that develop after implantation to allow the exchange of gas and nutrients with the mother.
![Thumbnail](../../../../../../figures.boundless-cdn.com/33594/square/asnmvwlvr3uvlxzxjkpb.jpg)
Development of the Extraembryonic Coelom
The extra-embryonic coelom is a cavity that contains the chorion. It is located between Heuser's membrane and the trophoblast.