Fig. 5.

Proposed models of smooth muscle organization at and surrounding the pylorus. A: illustrations of ICM (orange) and OLM (red) arrangement in cross sections of stomach, pylorus, and duodenum. B: schematic depiction of the gastric ligaments, as viewed laterally, ventrally, and in 3-D. Together, the pyloric OLM and contiguous gastric ligaments form a saddle-shaped muscle that surrounds the ICM (except on the ventral side); the ligaments extend anteriorly and superficially over the ventral stomach, toward the esophagus. Orientation is as follows: stomach is left, and dorsal is up.