A section through somite 9 and the caudal part of the midgut.
Observe:
1. The communication between the coelomic cavity and extraembryonic coelom.
2. The three subdivisions of mesoderm between the ectoderm and endoderm.
3. The separation of lateral plate mesoderm into splanchnic and somatic parts by the embryonic coelom.
Keywords: communication between coelomic cavity and extra-embryonic coelom, ectoderm, endoderm, intermediate mesoderm, lateral mesoderm, left dorsal aorta, midgut, myocoele, pronephric ridge (intermediate mesoderm), right umbilical vein, somatic mesoderm, somite 9 (C-5), splanchnic mesoderm, vitelline plexus
Source: Atlas of Human Embryos.