Question #487

Considering the development of the stomach, which of the following statements is correct?

Herniates out towards the yolk sac

In dextracardia rotates the opposite direction from normal

Starts to form during the 8th week

The greater omentum forms from the dorsal mesogastrium

The greater curvature initially forms ventrally

The stomach is a foregut structure. It starts to form from endoderm during the fourth week as the dorsal surface expands more rapidly than the anterior surface. The dorsal portion then rotates 90 degrees to the left and will form the greater curvature of the stomach.

A further rotation occurs around the dorsal-ventral axis. The inferior margin of the stomach rotates 90 degrees upwards such that the greater curvature now lies inferiorly.

The first rotation occurs in the opposite direction in situs inversus but not in dextracardia.

The stomach has both a dorsal and ventral mesentery. As it undergoes rotation the mesenteries are pulled laterally. The dorsal mesentery extends inferiorly and forms the greater omentum. The ventral mesentery is pulled to the right and forms the lesser omentum.

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