HISTOLOGICAL STRUCTURE OF DIGESTIVE TRACT OF JAPANESE QUAIL COTURNIX COTURNIX IN IRAQ.

The present study aims at knowing the histology description of the alimentary canal for Japanese quail Coturnix coturnix in Iraq. This study shown that alimentary canal wall consist of four basic layers which were mucosa, submucosa, muscularis layer and serosa or adventitia. Oropharynx cavity and tongue mucosa consists of keratinized stratified squamuse epithelium tissue. Salivary glands were distributed and large. Taste buds densely founded on posterior part of tongue. The lingual skeleton was recognized as cartilage tissue which supports striated muscle. The esophagus was with non-keratinized squamous epithelium tissue. Tunica mucosa forms longitudinal folds which contain many esophageal glands. Tunica muscularis consisted of two smooth muscle layer arranged as inter circular layer and outer longitudinal layer. The crop has large folds, thick muscles and many esophageal glands. The upper esophagus and the crop covered with adventitia layer while the serosa surrounds the lower esophagus. The stomach was lining with simple columnar epithelium tissue. In proventrticulus the superficial gastric glands were lining with short columnar cells. Muscularis mucosa was thin and surrounded the apical portions of the deep gastric glands. The deep gastric glands located in submucosa. The muscular layer consists of three smooth muscle layer. In the gizzard had been noticed stratum compactum layer which surrounds the simple tubular glands. The gizzard in Coturnix coturnix lacks muscularis mucosa for this reason we can not detect submucosa layer in it. The rectumof Coturnix coturnix has short villi. Tall columnar cells with well brush border lining the villi; moreover, there were goblet cells between them that increase toward the cloaca. Crypts of lieber kühn were well developed and containing goblet cells and enteroendocrine cells. Anterior part of the caeca has leaf shape villi, which become flat in posterior half, lymphatic cells and nodules increase in caeca and there were some crypts in lamina propria. [ABSTRACT FROM AUTHOR]