During the 5th week the developing stomach increases in length. Its dorsal border grows much faster than the ventral border and becomes highly convex resulting in the formation of the greater curvature of the stomach. Concurrently, deformation of the ventral border of the stomach forces it to become concave to form the lesser curvature of the stomach. The superior part of the greater curvature expands in an upward direction to form fundus of the stomach.