Development of mucosa of the human ileum.

Normal histology, glycogen and alkaline phosphatase have been studied in the mucosa of human fetal ileum between 28 and 140 days of gestation. From 112 days onwards, the perinuclear, supranuclear and infranuclear vacuolation, striate border, and basement membrane of the columnar epithelial cells of the villi, and the very close proximity of the latter to blood vessels, all support the idea that the cells are actively engaged in transport of materials. Alkaline phosphatase and glycogen become conspicuous in the cells at this stage. It is argued that by 112 days the epithelial cells of the ileum are absorbing glucose amniotic fluid as well as secreting mucus.