Rotation of the Stomach
Rotation of the stomach
In three diagrams.
First Diagram
- Begins ~ week 5
- Starts as a spindle-shaped tube
- Ventral and dorsal mesenteries attach the tube to the body walls
Recall that the portion of the dorsal mesentery that anchors the stomach can be more specifically referred to as the dorsal mesogastrium.
- Branches of the left and right vagus nerves (CN X) lie on ventral and dorsal surfaces.
Recognize that this is a simplification, as fibers from the right and left vagal plexuses intermix with each other and the celiac plexus, to some degree
Second Diagram
- Differential growth of the stomach and clockwise rotation along the longitudinal axis alters the course of the vagus nerve branches:
- The right vagus nerve now innervates the anterior/ventral surface of the stomach
- The left vagus nerve lies on the posterior aspect
- Notice that the cephalic and caudal ends remain in the midline.
- As the stomach rotates along the ventral-dorsal (aka, antero-posterior) axis, the caudal end is displaced towards the right, as the cephalic end towards the left;
- The ventral and dorsal mesenteries are also displaced to the right and left, respectively.
- Lesser curvature = ventral mesentery attachment.
- Greater curvature = dorsal mesentery attachment.
Though not shown here, the ventral mesentery gives rise to the falciform ligament, which secures the liver ventrally, and, the lesser omentum, which connects the liver and stomach and proximal duodenum.
The dorsal mesentery gives rise to the greater omentum, the apron-like fold of mesentery that attaches to the greater curvature of the stomach and drapes over the small intestine.
Mature Form