الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 342 |  |  |
| | | from | 342 | | |
Abstract
The present work concerned with the anatomical study of the digestive tract of two birds differ in feeding habits, the little owl, Athene noctua and the rock dove, Columba livia.
The little owl, recognizing as a fierce predator (carnivorous). Hunting is carried out mainly at dawn and dusk. The most frequent prey includes beetles, caterpillars, moths, spiders…..etc. Meanwhile, the rock dove feeds mainly on grains of rice, maize, millet and other cereals, pecked from the ground by beak then the tongue retracts for passing the food from the buccal cavity into the oesophagus then to the different segments of the digestive tract.
The morphological and anatomical studies on the digestive tract discussed the structural adaptations of the different segments structures of the digestive tract and the mode of feeding in the two bird species in two different seasons (summer and winter).
Different techniques were used in the present work including; Gross anatomy, Histology, Histochemistry , Scanning electron microscopy (SEM) and Biochemical Analysis.
I- General morphology of the digestive tract
a) Morphology of the digestive tract of the little owl
1- The oesophagus: is an elongated tube differentiated into cervical and thoracic oesophagus with numerous longitudinal folds incubating numerous flask -like oesophageal glands.
2- The stomach: consists mainly of two chambers (the proventriculus and ventriculus).The proventriclus consists of numerous deep and superficial gastric glands while the ventriculus consists mainly of tubular gastric glands which covered by thick koilin layer.
3- The small intestine: consists of duodenum and ileum .The duodenum has U-shaped appearance incubating the pancreas .The interior surface of the duodenum and ileum consists of numerous villi.
4- The large intestine: consists of enlarged two intestinal caecum, rectum, and cloaca.
b) Morphology of the digestive tract of the rock dove
1- The oesophagus: it is a long tube structure differentiated into three different regions: the cervical oesophagus without oesophageal glands, the out pocketing structure (crop) and the thoracic oesophagus which incubates oesophageal glands with a flask like appearance.
2- The stomach: consists of two main chambers : the proventriculus (glandular stomach) and the ventriculus (muscular stomach which covered with hard keratin structure (koilin layer).
3- The small intestine: consists of duodenum and ileum which externally cannot be differentiated except by their diameters.
4-The large intestine: consists of very short lymphatic type intestinal caeca, rectum, and cloaca.