A COMPARATIVE STUDY ON THE HISTOLOGICAL AND HISTOCHEMICAL FEATURES OF ESOPHAGUS IN OSTRICH CHICK

Due to economical worth of ostrich and also some unique characteristics of ostrich, having enough information about different scientific fields of ostrich, particularly its histological and histochemical features are necessary. On this research, histological structure of different parts of the esophagus was studied in 4 ostrich chicks. Tissue sections were prepared and stained by routine histological methods. The epithelium of the esophagus was stratified squamous and slightly keratinized. The lamina propria was consisted of a dense connective tissue with a few numbers of elastic fibers. This layer had simple tubuloalveolar mucus glands which were mainly tubular glands. The gland's secretions were contained carbohydrates. The type of carbohydrates was both neutral and acidic mucopolysaccarides. The lamina muscularis was present as a complete structure in the whole length of the esophagus. It was consisted of smooth muscle. The tunica submucosa was consisted of loose connective tissue and was composed of a few elastic fibers. The tunica muscularis was consisted of two layers of smooth muscle; the more thick inner circular and thinner outer longitudinal layers. The tunica serosa and adventitia contained relatively dense connective tissue. The results were compared with the available data on the other birds and also human and other mammals. There were similarities and differences between the ostrich and other species.