Anatomy of the ileum-intestinal tract of the human fetus at 16–22 weeks of ontogenesis

Aim – to obtain new data on the quantitative macromicroscopic anatomy of the iliac-intestinal region in the intermediate fetal period of human ontogenesis from the 16th to the 22nd week of development. Material and methods. The study was performed on 30 subjects of both sexes (18 female and 12 male fetuses) using the following methods: macro- and microscopic preparation, N.I. Pirogov sawing, histotopographic method, morphometry, and variation-statistical methods. All the morphometric data obtained were subjected to variation-statistical processing in Windows XP-based Excel 2010 and Statistics 13.0 application software packages. When testing statistical hypotheses in this study, the critical level of statistical significance (p) was assumed to be 0.05. The Student’s t-test was used to assess the reliability. A set of tools for macromicroscopic preparation of the fetus was used. Results. During the period of development in question, the position of the ileum has slight vertical deviations, which affects the formation and magnitude of the angle between the ileum and the cecum, as well as between the ileum and the ascending colon. The predominant shape of the cecum is cylindrical (80%), less often conical (20%). There is an uneven growth of the walls of the cecum, where the lateral wall prevails over the medial one, which is associated with the formation of flap structures. The ileo-intestinal opening is oval in shape, the frenules are weakly pronounced, with a more pronounced ileo-colon lip. Semilunar folds are differentiated on the mucous membrane of the cecum from 16-17 weeks, and a free muscle band is also determined. The omental and mesenteric bands are not pronounced. There is no morphological boundary between the appendix and the cecum. From 19-20 weeks, the presence of 1-2 gausters is noted. The quantitative parameters of the iliac-intestinal region are characterized by a gradual twofold increase in values.