Development of sacral vertebrae in human embryos and fetuses

Abstract

The aim of the study is to define the features of organogenesis and histogenesis of sacral vertebrae in human embryos, which predetermine the anatomical structure of the sacrum in postnatal ontogenesis. Material and methods. The authors studied human embryo serial sections at 17–23 stages from the Carnegie virtual embryological collection, total preparations and serial sections of the lumbosacral region of the fetal spine at 8–20 weeks of gestation without visible developmental anomalies. Histological sections were stained with hematoxylin and eosin; total preparations were stained with alizarin red and alcian blue. In addition, the study included 19 adult sacra from the anatomical collection of the Belarusian State Medical University. Results. It was found that consolidation of the anlages of the upper sacral vertebrae starts at the early stages of embryogenesis by the fusion of their costal-transverse processes. During the first half of intrauterine development, the arch and articular processes of the adjacent vertebrae remain separate from each other. In contrast to other segments of the spinal column, five primary centers of ossification are formed in the anlages of the upper sacral vertebrae