Rotation of the stomach during development results in movement of the left vagus nerve from its original position. Through approximately how many degrees of rotation does the nerve move, and what is its final position?
High-Yield Explanation
Rotation of the gut tube is a major event in the development of the gastrointestinal system. Parts of the tube rotate 270deg, but the proximal foregut, specifically that portion that forms the esophagus, rotates only 90deg. Looking from below (the standard CT or MRI view), this rotation is counterclockwise. This brings the left vagus nerve onto the anterior surface of the esophagus as it passes through the thorax.