The segment of the dorsal mesogastrium between its midline attachment and the spleen lies adjacent to the ventral surface of the left gonad, mesonephros, metanephros and suprarenal gland. It contains the dorsal pancreas and splenic vessels. The segment of the dorsal mesogastrium between the spleen and greater curvature increases in length to form a redundant fold called the greater omentum. The lesser sac that is enclosed by the dorsal mesogastrium enlarges as the greater omentum extends caudally. The pneumoenteric recess disappears.
Differential growth patterns in the stomach and duodenum bring the dorsal and ventral pancreas together in the mesoduodenum.
As the midgut loop elongates, its dorsal mesentery assumes a fan shape and is twisted in a counterclockwise direction.
The dorsal mesentery of the hindgut is pushed to the left by the midgut loop.
VENTRAL MESENTERY
No significant changes will occur in the lesser omentum and falciform ligament.
Source: Atlas of Human Embryos.