消化腺全英文學習教案

1、會計學1消化腺全英文消化腺全英文第一頁，共29頁。 Salivary glands* Parotid* Submandibular G.* Sublingual G.Three types of acini* serous* mucous * seromucousFunction: * moistening food * carbohydrate digestion * Secrete IgA 第2頁/共29頁第二頁，共29頁。Pancreas positioned retroperitoneally on the posterior wall of the abdominal cavity

2、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頁/共29頁第三頁，共29頁。Components of the exocrine pancreas consists of sero

3、us 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 ( tall columanr epth.) ma

4、jor duodenal papilla第4頁/共29頁第四頁，共29頁。第5頁/共29頁第五頁，共29頁。Function of pancreatic juice:* Trypsin, chymotrypsin & carboxypeptidase hydrolyse proteins; * ribonuclease & deoxyribonuclease split nucleic acids;* amylase hydrolyses starch & glycogen * lipase hydrolyses triglycerides into fatty aci

5、ds and monoglycerides * cholesterol esterase breaks down cholesterol esters into cholesterol and a fatty acid. 第6頁/共29頁第六頁，共29頁。Components of the Endocrine * Islands of Langerhans scattered throughout the exocrine pancreas. * Vascularization (many fenestrated cap.) is more extensive than that of the

6、 exocrine acini.* Three different types presentA-cells (20%): glucagon producerB-cells (75%): insulin producerD-cells (5%): somatostatin producer第7頁/共29頁第七頁，共29頁。第8頁/共29頁第八頁，共29頁。Liver* largest gland ( 2% of body weight in adult). * receives both venous & arterial blood through the portal V. (75

7、%) & 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頁/共29頁第九頁，共29頁。 Structures of liver lobules* six-sided prism with a central V. at its centre* delimite

8、d 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頁/共29頁第十頁，共29頁。 Portal areas*definition: a area found in the angles where adjacent hepatic lobules meet.* c

9、omponents: CT. + portal triadinterlobular Ainterlobular Vinterlobular bile duct第11頁/共29頁第十一頁，共29頁。第12頁/共29頁第十二頁，共29頁。第13頁/共29頁第十三頁，共29頁。Sinusoids* dialated anastomosing venules between the hepatic plates * blood pathway: periphery central v. * Kupffer cells lined in the wall of sinusoids* EM: signif

10、icant gaps numerous fenestration incomplete basal lamina第14頁/共29頁第十四頁，共29頁。第15頁/共29頁第十五頁，共29頁。第16頁/共29頁第十六頁，共29頁。Hepatocytes* make up about 80% of the cells in the liver.* typically large polyhedral cells with large round centrally located nuclei. * abundance of organelles related to the functionsMi

11、tochondria: 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頁/共29頁第十七頁，共29頁。Hepatocyte function* Produce bile* media

12、te 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頁/共29頁第十八頁，共29頁。Bile CanaliculiDefinition: tubular space limited by plasma membrane of two a

13、djacent 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頁/共29頁第十九頁，共29頁。第20頁/共29頁第二十頁，共29頁。Blie canaliculi stained by silver impregnation第21頁/共29頁第二十一頁，共29頁。

14、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 & hepatocytes.第22頁/共29頁第二十二頁，共29頁。第23

15、頁/共29頁第二十三頁，共29頁。*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頁/共29頁第二十四頁，共29頁。 Portal V interlobular V Hepatic Ainterlobular A sublobular

16、Vsinusoids central Vhepatic VInferior vena cava(75%)(25%)第25頁/共29頁第二十五頁，共29頁。Bile canaliculi periperal bile ductules ( Herings )interlobular bile duct Left & right hepatic ductsCommon hepatic ductCommon bile ductDuodenum papilla Cystic ductGall bladder第26頁/共29頁第二十六頁，共29頁。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 ce