消化腺全英文学习教案

1、会计学1第一页，共30页。Components digestive glands found in the wall of digestive tract accessory digestive glands:salivary glands / pancreas / liver General structure* Parenchyma (functional portion of an organ, as distinguished from the supporting tissue):acini / gland cellsduct* Stroma (unfunctional portio

2、n of an organ):capsule, CT inside.第1页/共29页第二页，共30页。 Salivary glands* Parotid* Submandibular G.* Sublingual G.Three types of acini* serous* mucous * seromucousFunction: * moistening food * carbohydrate digestion * Secrete IgA 第2页/共29页第三页，共30页。Pancreas positioned retroperitoneally on the posterior wal

3、l of the abdominal cavity at the level of the second and third lumbar vertebrae. no distinct capsule, but is covered by a thin layer of LCT both an exocrine & endocrine gland. * exocrine part: produces pancreatic juice * endocrine part: produce hormones第3页/共29页第四页，共30页。Components of the exocrine

4、 pancreas consists of serous glands acini filled with acidophilic zymogen granules intercalated duct extends into the centre of the acini, which is lined by centroacinar cells duct system: intercalated ducts (low columnar or cuboidal epith.) Interlobular ducts (columnar epith.) Main pancreatic ducts

5、 ( tall columanr epth.) major duodenal papilla第4页/共29页第五页，共30页。第5页/共29页第六页，共30页。Function of pancreatic juice:* Trypsin, chymotrypsin & carboxypeptidase hydrolyse proteins; * ribonuclease & deoxyribonuclease split nucleic acids;* amylase hydrolyses starch & glycogen * lipase hydrolyses tr

6、iglycerides into fatty acids and monoglycerides * cholesterol esterase breaks down cholesterol esters into cholesterol and a fatty acid. 第6页/共29页第七页，共30页。Components of the Endocrine * Islands of Langerhans scattered throughout the exocrine pancreas. * Vascularization (many fenestrated cap.) is more

7、extensive than that of the exocrine acini.* Three different types presentA-cells (20%): glucagon producerB-cells (75%): insulin producerD-cells (5%): somatostatin producer第7页/共29页第八页，共30页。第8页/共29页第九页，共30页。Liver* largest gland ( 2% of body weight in adult). * receives both venous & arterial blood

8、 through the portal V. (75%) & hepatic A (25%), respectively.* CT of capsule extended into the parenchyma, forming “ classical” liver loblules ( basic structure units).* functions as an exocrine gland (secreting bile).第9页/共29页第十页，共30页。 Structures of liver lobules* six-sided prism with a central

9、V. at its centre* delimited by interlobular CT * portal triads in the corner of lobules (portal area)* anastomosing plates of hepatic cells extended radially from the central V.* sinusoids form between hepatic plates第10页/共29页第十一页，共30页。 Portal areas*definition: a area found in the angles where adjace

10、nt hepatic lobules meet.* components: CT. + portal triadinterlobular Ainterlobular Vinterlobular bile duct第11页/共29页第十二页，共30页。第12页/共29页第十三页，共30页。第13页/共29页第十四页，共30页。Sinusoids* dialated anastomosing venules between the hepatic plates * blood pathway: periphery central v. * Kupffer cells lined in the wa

11、ll of sinusoids* EM: significant gaps numerous fenestration incomplete basal lamina第14页/共29页第十五页，共30页。第15页/共29页第十六页，共30页。第16页/共29页第十七页，共30页。Hepatocytes* make up about 80% of the cells in the liver.* typically large polyhedral cells with large round centrally located nuclei. * abundance of organelles

12、 related to the functionsMitochondria: energy providingRER: protein synthesisSER: bile formation / metabolism of lipids and hormones / detoxification.Lysosome: replacement and defenceMicrobody: detoxification.Inclusions: glcogen particles, lipid droplets and pigments.第17页/共29页第十八页，共30页。Hepatocyte fu

13、nction* Produce bile* mediate carbohydrate reserves glycogen is degraded to glucose under regulation of hormones* Blood lipid metabolism* Synthesis of plasma proteinsalbumin: major plasma proteinfibrinogenthrombinclotting factor III第18页/共29页第十九页，共30页。Bile CanaliculiDefinition: tubular space limited

14、by plasma membrane of two adjacent hepatopcytes.Structure:LM: network-like structures are seen by silver impregnationEM: * plasma membrane of adjacent hepatocytes form the wall of bile canaliculi* tight junctions form seals第19页/共29页第二十页，共30页。第20页/共29页第二十一页，共30页。Blie canaliculi stained by silver impr

15、egnation第21页/共29页第二十二页，共30页。Perisinusoidal sapce (space of Disse) a space between the endothelium & hepatocyte be visible under EM occupied by numerous microvilli of hepatocytes filled with plasma fat-storing cells (storing fat & vitamin A) a site for exchange between the blood & hepatoc

16、ytes.第22页/共29页第二十三页，共30页。第23页/共29页第二十四页，共30页。*cell junction surface* Perisinusoidal surface: face to perisinusoidal space * bile canalicular surface: face into the bile canaliculusInterlobule A.&V.Three types of functional surface in hepatocyte第24页/共29页第二十五页，共30页。 Portal V interlobular V Hepatic

17、 Ainterlobular A sublobular Vsinusoids central Vhepatic VInferior vena cava(75%)(25%)第25页/共29页第二十六页，共30页。Bile canaliculi periperal bile ductules ( Herings )interlobular bile duct Left & right hepatic ductsCommon hepatic ductCommon bile ductDuodenum papilla Cystic ductGall bladder第26页/共29页第二十七页，共

18、30页。Classification of Lobules1.Classic lobule: A hexagonal structure with the central vein at its center; at the six corners of the lubule are hepatic triads.2. Portal lobule: A triangular structure with the portal area at its center. Three central veins are found at the peripheral boundary points.3. Liver acinus: An elongate diamond-shaped lobule; a