关键词: 江豚, 肠, 肝, 胰, 解剖学

Abstract: The length of the intestines is about 7-11.2 times the body length (Table 1). The porpoise has no caecum and Paneth cells. Brunner's glands are lacking in the duodenum.Apart from the size of the plica and the thickness of the intestinal wall,there is no distinct difference between the small and the large intestines.Reticular plicae are well developed in the duodenal ampulla which has no villi in the mucosa.The lower part of the intestinal glands of the ampulla is full of mucous cells which is much less in number in the foetus. No sphincter muscle can be found between the ampulla and the duodenum proper. In the duodenum proper the ratio of the thickness of the circular muscle layer to the longitudinal muscle layer is about 3.5:1 and neither lymphtic nodules nor mucous cells resembling that of the ampulla has been found in both adult and foetus.Villi are scarce and short in the jejunum and ileum and they are absent in the colon.Goblet cells are plentiful in the rectum.The anal canal is about 5 cm.in length and its mucosa is covered with stratified squamous epithelium.The submucosa of the anal canal at about 1 cm.away from the end of the rectum possesses well-developed anal tonsils about 1.5mm, in diameter.The weight of the liver of the finless porpoise is about 2.4% times the body weight.The falciform,the round and part of the coronary ligaments are connected with the ventral surface of the liver. The hapatic veins at the terminal near the inferior vena cave are not distended in the porpoise. The interlobular vein of the liver has a wide lumen and a circular smooth muscle only 26μm.in thickness.The pancreas is located at the left side of the duodenal ampulla and on the back of the main stomach and pyloric stomach. It is enclosed in the dorsal lobe of the omentum majus.The pars papillaris ampullae of the Vate-rian ampulla at the end of the hepato-pancreatic duct with a narrow lane penetrates the circular muscle layer of the duodenum and bears the tubuloa-Iveolar glands occurred almost exclusively by the serous cells. The islets of langerhans were scattered in the lobules of the pancreas. There are three islets in one circle of the parenchym of the pancreas about 1mm.in diameter and the size of each islet is about 65 x 52 urn. The numerical ratio of A to B cells is roughly 1:2.

Key words: Black finless porpoise, Neophocaena asiaeorientalis, Intestines, Liver, Pancreas, Anatomy