The gut is twisted logically

The human intestine, much longer overall than the human body, is tightly looped within the body cavity in a pattern that is very similar between individuals, and characteristic of species. A study of gut morphogenesis in the chick, combining cellular and developmental biology, biophysics and mathematical modelling, shows that the looping complex shape of the vertebrate gut is a simple consequence of mechanics. As a body grows, the gut inside grows faster. It is anchored at each end and suspended by a muscular sheet called the mesentery, so is forced into loops. The looping pattern is determined solely by the elasticity, geometry and relative rates of growth of mesentery and gut, but the various twists and turns and loops are very reproducible, occurring with the same number in the same location from individual to individual.