Streptopelia senegalensis and White-breasted Kingfisher, Halcyon smyrnensis

The aim of the current work was to study the histological structures of glandular stomach, the proventriculus and compare it in two types of Iraqi wild birds according to differences in diets. The birds are, Laughing dove, Streptopelia senegalensis which comprised the grainivorous bird and white breasted Kingfisher Halcyon smyrnensis which comprised the carnivorous bird. The results exhibited that the wall of the stomach (proventriculus) of two birds consists of the four layers of typical tubular organ: tunica mucosa, submucosa, muscularis and serosa. The tunica mucosa of two birds consisted of three layers, epithelium, lamina properia and muscularis , the free surface of two birds is covered with circular plicae modified from of the mucosa, The surface lining cells of this folds in both of birds is simple columnar with clear cytoplasm. The lamina propria is constituted by connective tissue with blood vessels and lymphocitary infiltration. As well as simple tubular glands. Notice that these glands are lining by simple columnar in white breasted kingfisher while simple cuboidal to columnar in laughing dove. Muscularis mucosa was a smooth muscle fibers, appears scattered along the lamina propria in laughing dove surrounds the apical part of deep proventricular glands, and extend inside the proventricular folds and entirely around the deep proventricular glands in white breasted kingfisher. Submucosa layer occupy most of the real area of the proventriculus wall containing numerous deep proventricular glands that occupy great part of submucosa. This layer is thicker in kingfisher as compared with laughing dove. Each secretory region is a well-defined unit and enclosed by a connective tissue capsule contains bloods vessels and nerves. These gland are compound tubular branched glands, each gland consists of numerous of secretory tubules. These tubule leads to ducts and open into central collecting duct that opens in the proventricular lumen. The secretory tubules of deep glands lining by simple cuboidal cells represent chief cells that secreting hydrochloric acid and pepsinogen. the tunica muscular (tunica muscularis) of two birds consist of two layers, inner circular muscle layer and outer longitudinal muscle layer, inner layer is thicker in kingfisher as compared to laughing dove. Between these two muscular layers, blood vessels and nervous plexus (Auerbach) are found. The tunica serosa consisted of connective tissue contains nerves, blood vessels and ganglionic cells of serous plexus.