Data regarding the structural feature of nervous elements in the bile ducts during intrauterine life

The nervous elements of the extrahepatic bile ducts were studied on serial sections prepared from rabbit and human embryos and foetuses, using silver impregnation techniques. In the gallbladder of rabbit embryos and foetuses, the nervous elements are absent, whereas the bile ducts possess a dense parasympathetic vegetative plexus. In human embryos, the muscular layers and submucosa of the gallbladder and bile ducts have well developed parasympathetic plexuses and a sympathetic subserous plexus, without nerve cells, respectively. The histotopical identification of nervous elements in the bile ducts allows the distinction of parasympathetic plexuses from the sympathetic ones.