Now that you have a neural tube, you start to bump into a layer endometrium, which is in the mother's womb. Now we have started the process of implantation. The endometrium is building up around you, while you zona pellucida is disintegrating. This is called apposition. The trophoblasts start to spread through the endometrial tissue. This is called adhesion. But your not the only thing that's changing...
The endometrium has built up around you, and it has collections of blood. The blood starts to pool, and the trophoblasts start to change. They start to fuse, and grow out and into the endometrium. Now that they are different, of course the need a new name! They are now called syncitiotrophoblasts. That is the end of implantation, but we need to know what everything you just learned does.
The endoderm makes the gastrointestinal tract, the lungs, the liver, and the pancreas.
The mesoderm makes the muscles and bones.
The ectoderm makes the skin, nervous system, and the glands. This is you developed properly.
