Histomorphological and developmental study of tongue in Canadian ostrich embryo ((Struthio camelus)

This study is due to investigate the histological and histochemical properties of the tongue of the embryo and one day old ostrich chickens. Twelve eggs in various embryonic stages (22، 26، 30 and 36 embryonic days) and three one day chicks were used. The specimens from whole of tongue were collected and after preparing tissue were stained by histological staining methods include H & E،Masson trichrome، PAS and Alcian blue. Tissue sections were studied for their histological development. In results، we concluded the type of the epithelium in dorsal and ventral surface of tongue in day 22 was nonkeratinized stratified squamous epithelium. There were any changes in type of epithelium in other days، but the thickness increased due to age. In day 22 and 26 irregular bumps was seen in tongue epithelium. In all of specimens، thickness of epithelium in dorsal surface was more than ventral. The beginning of mesenchymal connective tissue was observed in 22 days of age and at the one-day old chicks was evolved and was modified dense irregular. At age 22 days، the muscle bundles scattered in directions transverse and longitudinal striated muscle، connective tissue was observed that the increase in surface area increases the rate of. 22 days of age. There were hyaline cartilage tissue sections in the deep zone of connective tissue. It was observed two side pieces and one piece in midsection. The glands began at 30-day-old and at the one-day old chicks were with a maximum evolution. Response to histochemical staining was positive for PAS and alcian blue and PAS''s response was more intense، indicating higher levels of neutral mucin secretion glands.