Histological study of hepatic bile ducts in the common quail (Coturnix coturnix)

The aim of this investigation was to study the histological structure of the hepatic bile ducts in common quail (Coturnix coturnix). Twenty clinically healthy adult female and male common quail were used. Histological results showed that the hepatic bile ducts possessed tunica mucosa, tunica muscularis and tunica serosa. The tunica mucosa forms some simple folds which appeared to be irregularly distributed over the whole luminal surface and were almost non isometric. The mucosa was lined by non ciliated simple cuboidal to columnar epithelium which was covered by a continuous striated border of microvilli. No goblet cells were observed among epithelial cells. Deep invaginations of the surface epithelium were observed to have grown down into the underlying mesenchyme, showing a tubular gland like appearance. The lamina muscularis mucosa was absent. The thin lamina propria-submucosa was contained loose connective tissue which consisted of numerous diffuse lymphatic aggregations. No glands were observed in lamina propria-submucosa. The tunica muscularis was composed of an outer circular and an inner longitudinal layer of smooth muscle fibers. The loose connective tissue of tunica serosa or adventitia was made up of blood vessels, adipose tissues, parasympathetic ganglion and nerve fibers. No significant sex-based differences were found. In conclusion, the histology of the hepatic bile ducts of the Coturnix coturnix was similar to that in Alectoris chukar except for the epithelial downgrowths and tunica muscularis.