Morphometrical and Histochemical study of glandular stomach (Proventriculus) in local domestic male ducks (Anas Platyrhynchos)

The present work explores morphometric and histochemical foundations of the wall of proventriculus in adult domestic male ducks. To achieve this study, six healthy adult ducks were purchased from local vendors in Mosul province. All birds were sedated. Their stomachs were removed after being dissected to achieve the gross description and measurements of the proventriculus, including the length and diameter of cranial, middle, and caudal regions of the proventriculus. Small tissue pieces 6-8 mm in length from three regions of proventriculus were processed for histomorphological studies using hematoxylin and Eosin stain, combined PAS-AB pH 2.5, toluidine blue, and Masson's trichrome stains. The finding showed that the proventriculus connects with the esophagus from the cranial side and the muscular stomach from the caudal side. It was a thin elongated oval tubular organ. Histologically, the mucosa of the proventriculus revealed the presence of folds and sulci-like structures covered by simple columnar epithelium. The tunica submucosa consisted of many signs of profound and straightforward sub-mucosal glands supported by connective tissue septa and extended from the basal part of the diverged gland through the lamina propria, which was organized in a conical manner (adenomere). Tunica Muscularis appeared as a double-layer coordinated in the form of inner longitudinal and outer circular ones. Finally, serosa consists of fibrous tissue, vessels, fatty tissue, and nerve plexuses studded by the mesothelial cells. The highest thickness of the four layers of mucosal, submucosal, muscular, and serosal layers in the distal part of ‎the proventriculus. Histochemical PAS staining positively reacted with epithelial tunica mucosa and wall of proventricular glands.