Histological Study on the Oesophagus and Crop in Various Species of Wild Bird

Abstract

The histology of the oesophagus and crop was studied in six species of birds: Rock Dove, Collared Dove, Rose-ringed Parakeet, Kestrel, House Sparrow and Linnet. In species, the epithelium of oesophagus and crop was a keratinised stratified squamous. The lamina propria was a loose connective tissue containing glands. Glands were either purely mucous or seromucous (mixed). In the rock dove, rose-ringed parakeet and collared dove, there were no glands either in the cervical part of oesophagus or in the crop. There were differences in the histochemistry of glands’ secretions. The muscularis mucosa was present as a thick layer of smooth muscle fibres. The tunica submucosa was a loose connective tissue containing vessels and nerves. The tunica muscularis consisted of smooth muscle and was surrounded by the tunica adventitia at the cervical part of the oesophagus and crop, and by the tunica serosa at the thoracic part of the oesophagus.