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دراسة شكليائية ونسجية للقناة الهضمية في سمكة الخشني Liza abu Heckel.1843 == Morphological And Histological Study of The Digestive Tract In Liza Abu (Heckel, 1843)
Author name:
حنان رعد ضياء حسين
Supervisor name:
وجدان بشير عبد
General topic:
Biology
Specific topic:
Zoology - Histology
Degree:
Master
University:
University of Baghdad - Ibn Al-Haytham College Of Education For Pure Sciences - Department Of Biology
Language:
Arabic
University location:
Baghdad
First pages:
24T2879 - p.pdf
Abstract:
The morphological and histological structure of digestive tract in one species of Iraqi fish that resides in Iraqi inland fresh water (Liza abu) was studied. In this study used (43) fish were in different lengths, the gut of these fish have removed to study the relationship between the length of gastrointestinal tract and the standard body length as well as for morphological and histological study. The value of relative digestive tract length (RGL) was 2.9. Intestine was the longest part of the digestive tract, the average length of intestine was (32 cm). The shape of the folds of the mucous membrane lining the walls of digestive tract showed some differences in different parts of digestive tract, in esophagus the folds were longitudinal running along the wall and it was straight, unbranched and the mean of their number was (9 - 8) folds. In the stomach the folds were longitudinal and (7 - 6) in their number, they were branched into fingerlings structures. In pyloric caeca, anterior and posterior part of intestine and rectum the folds were fingerlings in shape, unbranched and their number were (20 - 19), (27 - 26), (25 - 23), (19 - 18) respectively. Histological study was shown that the wall of the digestive tract is consist of four major coats, from the inside to the outside they were as follows : Tunica Mucosa which characterized by its clear three parts, epithelial tissue, lamina propria and muscularis mucosa. Epithelial tissue in esophagus was thick stratified squamous epithelium, in stomach was thin simple columnar epithelium and gradually increase in length in each of pyloric caeca, intestine and rectum and it was simple columnar epithelial tissue. Mucous which is secreted in esophagus is made of a large proportion of neutral and acidic mucopolysaccharide, while the mucous secreted in the cardiac stomach consist of a large proportion of neutral mucopolysaccharide and less proportion of acidic mucopolysaccharide, either, in the pyloric stomach is consist of very small proportion of both neutral and acidic mucopolysaccharide, in pyloric caeca mucous consist of a small proportion of neutral mucopolysaccharide and less proportion of acidic mucopolysaccharide, and the mucous secreted in an anterior, posterior parts of intestine and rectum consist of small proportion of acidic mucopolysaccharide and large proportion of neutral mucopolysaccharide. Lamina propria consists of connective tissue containing capillaries and lymphoid cells and it represent the basis of the folds, in the cardiac stomach it contains simple tubular glands. Muscularis mucosa characterized by the presence of muscle fibers that are not continuous, the higher thickness of this layer was in pyloric stomach. Tunica Submucosa consists of connective tissue that contains capillaries, the higher thickness of this coat was in the stomach and less thickness of this coat was in the rectum. Tunica Muscularis consists of two layers of smooth muscle fibers, the internal layer has a circular arrangement, the external layer has a longitudinal arrangement in stomach, pyloric caeca, intestine and rectum. either in esophagus tunica muscularis was arranged in inverse manner. The circular and longitudinal muscle fibers in esophagus were skeletal muscle fibers, and they were smooth and non - striated in stomach, pyloric caeca, intestine and rectum. the higher thickness of this coat was in the stomach and less thickness was in the rectum Tunica Serosa is present in all regions of digestive tract.
