Streptopelia senegalensis and White-breasted Kingfisher, Halcyon smyrnensis

Abstract

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.