Digestive glands - 浙江大学教学信息化平台.ppt

Digestive glands,General outline,distributed in the wall of digestive tract esophageal glands, gastric glands and intestine glands,large digestive glands,outside the wall of digestive tract salivary glands, liver and pancreas,Large salivary glands,Include parotid, submandibular and sublingual glands are compound tubuloacinar glands are composed of acini and ducts,Large salivary glands,Acinus :,acinar epithelium: simple cuboidal or pyramidal cells myoepithelial cell basal membrane,Structure:,Be divided into,Serous aciniMucous aciniMixed acini,Serous acini,cytoplasma are deep stained nucleus are spherical in shape and near the base secretion is thin, contains salivary amylase and a little mucus,Serous acini and striated duct,Mucous acini,cytoplasma are light-blue stained nucleus are flattened ovoid shaped and close to the base secretion is thick; contains mucoprotein,Mucous acini,Mixed acini,consist of above two kinds of cells demilunes: several serous cells are attached eccentrically to the mucous acini,Mixed acini,Ducts:,Intercalated ducts,diameter: thinnestwall: simple low cuboidal epithelium,Striated duct (secretory duct),wall: simple columnar epithelium; the nucleus is near the cell apex; cytoplasm is acidpphilic; has basal striations EM: the basal striations created by membrane infolding and mitochondia reabsorbing sodium and excreting potassium; transport water and ions,导管(duct),闰管：单扁或矮立方；短而细,纹状管,单柱，胞质嗜酸性，核靠近细胞顶部基底纵纹（EM：质膜内褶）转运水和电解质（保钠排钾）,小叶间导管：假复柱总导管：复扁,Intercalated duct,Striated duct,Intercalated ducts and striated ducts,Interlobular duct,Wall: pseudostratified epithelium,Main duct,Near its orifice become stratified squamous epithelium,Parotid gland,pure serous gland longer intercalated duct secrete 25% of saliva, more salivary amylase, less mucus,Parotid gland,Submandibular gland,mixed gland. Serous acini are more than mixed or mucous acini short intercalated duct, longer striated duct secrete 70% of saliva, less salivary amylase, more mucus,Submandibular gland,Sublingual gland,mixed gland, mucous and mixed acini predominant, more demilune without intercalated duct, obscure striated duct secrete 5% of saliva, most mucus,Sublingual gland,Pancreas,Exocrine portion:,the features of the acini,a single layer of pyramidal serous cells surrounded by basal lamina, without myoepithelial cells centro-acinar cells: the epithelial cells of intercalated duct penetrating into the lumen of the acinus,the feature of ducts,the intercalated duct is long and has branches no striated ductmain duct: lined by simple columnar epithelium in which a few goblet cells and endocrine cells can be seen,The functions of exocrine portion,Secret abundant trypsinogen, chymotrypsinogen, amylase, lipase, sodium bicarbonate and trypsin inhibitor,Pancreas,Pancreas ( show centro-acinar cells and intercalated ducts),Endocrine portion (pancreatic islet):,rounded clusters of cells embedded within exocrine pancreatic tissue are divided into three kinds of cells: A, B, and D cells fenestrated capillaries are among the cells,Pancreas (show pancreatic islet),Endocrine portion,Other cells,PP cells: pancreatic polypeptideG cells: gastrin,A cells,B cells,D cells,Liver,Liver lobule,Portal area,Hepatic platesSinusoid Central vein,Interlobular arteriesInterlobular veinsInterlobular bile ducts,Functions of liver:,bile secretion synthesize: protein, glycogen, cholesterin detoxification and inactivation defence hemopoiesis,Human liver,Pork liver,Liver lobule:,hepatic plates: are composed of a single layer of hepatocytes arranged in radial sinusoid: situated between the hepatic plates, forming a complex network central vein: occupies the centre of the liver lobule,Liver lobule,Hepatic plates,Hepatic cords and liver sinusoids,Hepatocytes,polyhedral in shape, eosinophilic cytoplasm, one or two large rounded nuclei with one or 2 typical nucleoli EM: Mi, RER, SER, Golgi apparatus, lysosomes, microbodies, inclusions,Mitochondria,provide the energy for the hepatocytes,Rough endoplasmic reticulum,synthesize some plasma proteins,Golgi apparatus,participate in the formation of bile and lipoprotein,Smooth endoplasmic reticulum,synthesize bile, triglyceride and LDL metabolism of the lipid, hormones and cholerythrin inactivate steroid hormone biotransformation of some materials detoxification of noxious substances,Lysosomes,actively participate the metabolism of hepatocyte and renewal of organelles play a role in metabolism and transport of cholerythrin storage of iron,Microbodies,detoxification: catalase and peroxidase; reduce the hydrogen peroxide into H2O,Inclusions,include glycogen, lipid droplets, pigment etc;These contents vary according to physiologic state of human body,Bile canaliculi,between two adjacent hepatocytes the membrane of hepatocyte projects to the lumen, forming many microvilli the cell membranes near the bile canaliculi are firmly bound by junctional complexes,Bile canaliculi,Liver sinusoid,spaces between the hepatic plates irregular in shape composed of only one discontinuous layer of fenestrated endothelial cells, no diaphragm, no basement membrane Kupffer cells are located within the sinusoid cavities,肝血窦 Hepatic sinusoid,分布：位于肝板之间,结构：,内皮不连续，有孔无隔膜，吞饮小泡，无基膜,功能：,通透性大，有利于肝细胞与血液间物质交换,枯否细胞,窦周隙： 贮脂细胞、网状纤维,（Disse 隙）,Kuffer cells in liver sinusoid,Liver sinusoid and space of Disse,Space of Disse,separates the endothelium from the hepatocytes contains some reticular fibers and fat-storing cells,肝细胞超微结构,Portal space:,the connective tissue separating the lobules including,Interlobular arteriesInterlobular veinsInterlobular bile ducts,Portal spaces,Blood circulation:,portal V.,interlobular V.,sinusoids,hepatic A.,interlobular A.,central V.,sublobular V.,hepatic V.,（functional vessel),(nutrient vessel),肝的血液循环：,门V 小叶间V,肝A 小叶间A,肝血窦 中央V 小叶下V,肝V,下腔V,Blood vessels of liver,(prepared Chinese ink injection through portal vein),Discharge way of bile:,Bile canaliculi,Herings canals,Interlobular bile ducts,Hepatic duct,Common bile duct,Gallbladder,Cystic duct,duodenum,胆汗排出途径：,肝细胞,胆小管,闰管,小叶间胆管,左、右肝管,胆总管,十二指肠,胆囊,胆囊管,Gallbladder,mucosa,Simple columnar Epi. , no Goblet cellsLaminar propria: C.T.,muscle layer: composed of an inner circular, an outer longitudinal layers of smooth muscle,adventitia: most are fibrosa, some are serosa,Gallbladder,Mi：供能RER：合成蛋白质（白蛋白、纤维蛋白原、酶）SER：合成、转运胆汁；糖、脂、类固醇激素 代谢；解毒 Golgi：加工运输蛋白质、分泌胆汁lysosome ：自噬、异噬、胆红素转运、储存铁 微体：解毒,肝细胞超微结构及其相关功能：,复习思考：,简答,胰岛外分泌部，胰岛，肝血窦，窦周隙胆小管，肝细胞邻接面,问答,联系超微结构说明肝细胞的功能,