Embryo of the GI tract
The yolk sac is mesodermal in origin. The mesoderm gives rise to the splanchopleure, which gives rise to the tube of the GI tube, foregut, midgut and hindgut. Paraxial, intermediate and lateral plates are near the neural tube and are parts of the mesoderm. The Paraxial intermediate gives rise to somites, limbs start growing from a lateral plate and the intermediate plate gives rise to the urogenital system.