[Pathology of developmental defects of the digestive system in human embryos].

Total incidence of the alimentary system defects was 1.05 +/- 0.12% in the non-selected material of medical abortions performed at 5-12 weeks of the intrauterine development. Atresia and stenosis of the duodenum are described for the first time in the embryos of the above age, the possibility of differential diagnosis between physiological and pathological atresia is established. The connection between the ducts of the ring-like head of pancreas and ductus choledochus is observed thus confirming the hypothesis of the additional pancreatic part developing from the ventral anlage. Diagnosis of Mekkel's diverticulum became possible beginning from stage 17. The existence of atresia, stenosis and gastro-intestinal tract doubling in the embryos of the above age indicate that at least some of these defects are not connected with a secondary damage of the intestinal tube due to circulation disturbances, recanalization or inflammation but represent a primary developmental anomaly arising in the early ontogenesis.