Figure 17. RF-I (green) and S-I (blue) in posterior stomach and ileum of female and male adults: A: female; ileum is to right; two RF-I axons (arrows) are visible coursing along ileum towards pyloric ring. B: male; ileum is to right and posterior stomach to left; network of S-I axons are visible in posterior stomach; three RF-I axonal connections to the ring are indicated by arrows.