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1、單擊此處編輯母版標(biāo)題樣式,單擊此處編輯母版文本樣式,第二級(jí),第三級(jí),第四級(jí),第五級(jí),*,Digestive System,Digestive Glands,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 supporti
2、ng tissue,):,acini,/gland cells,duct,*,Stroma,(,unfunctional,portion of an organ,):,capsule,CT inside.,Salivary glands,*,Parotid,*,Submandibular G.,*,Sublingual G.,Three types of acini,*,serous,*,mucous,*,seromucous,Function:,*,moistening food,*,carbohydrate digestion,*,Secrete IgA,Pancreas,position
3、ed,retroperitoneally,on the posterior wall 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,Componen
4、ts of the exocrine 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
5、 pancreatic ducts(tall,columanr epth,.),major duodenal papilla,Function of pancreatic juice:,*,Trypsin,chymotrypsin,&,carboxypeptidase,hydrolyse proteins;,*,ribonuclease,&,deoxyribonuclease,split,nucleic acids;,*,amylase,hydrolyses starch&glycogen,*,lipase,hydrolyses triglycerides into fatty acids,a
6、nd monoglycerides,*,cholesterol esterase,breaks down cholesterol,esters into cholesterol and a fatty acid.,Components of the Endocrine,*,Islands of Langerhans scattered,throughout the exocrine pancreas.,*,Vascularization(many,fenestrated,cap,.)is more extensive than,that of the exocrine acini.,*,Thr
7、ee different types present,A-cells(20%):,glucagon,producer,B-cells(75%):,insulin,producer,D-cells(5%):,somatostatin,producer,Liver,*largest gland(2%of body,weight in adult).,*receives both venous&arterial,blood through the portal V.,(75%)&hepatic A(25%),respectively.,*CT of capsule extended into the
8、 parenchyma,forming,“classical liver loblules(basic structure units).,*functions as an exocrine gland(secreting bile).,Structures of liver lobules,*,six-sided prism with a central V.at its centre,*,delimited by interlobular CT,*,portal triads,in the corner,of lobules(,portal area,),*,anastomosing pl
9、ates of hepatic,cells,extended radially from the,central V.,*,sinusoids,form between hepatic,plates,Portal areas,*,definition:,a area found in the angles where adjacent hepatic lobules meet.,*,components:,CT.+portal triad,interlobular,A,interlobular,V,interlobular,bile duct,Sinusoids,*,dialated anas
10、tomosing venules between the hepatic plates,*,blood pathway:,periphery central v.,*,Kupffer cells,lined in the wall,of sinusoids,*,EM:,significant,gaps,numerous,fenestration,incomplete basal lamina,Hepatocytes,*,make up about 80%of the cells in the liver,.,*,typically large polyhedral cells with lar
11、ge round,centrally located nuclei.,*,abundance of organelles related to the functions,Mitochondria:,energy providing,RER:,protein synthesis,SER:,bile formation/metabolism of lipids and,hormones/detoxification.,Lysosome:,replacement and defence,Microbody:,detoxification.,Inclusions:,glcogen particles
12、,lipid droplets,and pigments.,Hepatocyte function,*,Produce bile,*,mediate carbohydrate reserves,glycogen is degraded to glucose under,regulation of hormones,*,Blood lipid metabolism,*,Synthesis of plasma proteins,albumin:,major plasma protein,fibrinogen,thrombin,clotting factor III,Bile Canaliculi,
13、Definition:,tubular space limited by,plasma membrane of two,adjacent hepatopcytes.,Structure:,LM:,network-like structures are seen by,silver impregnation,EM:,*,plasma membrane,of adjacent hepatocytes,form the wall of bile canaliculi,*,tight junctions form seals,Blie canaliculi stained by silver impr
14、egnation,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,.,*,cell junction surface,*,Per
15、isinusoidal surface:,face to perisinusoidal space,*,bile canalicular surface:,face into the,bile,canaliculus,Interlobule A.&V.,Three types of functional surface in hepatocyte,Hepatic Blood Supply,Portal V interlobular V ,Hepatic Ainterlobular A ,sublobular V,sinusoids,central V,hepatic V,Inferior ve
16、na cava,(75%),(25%),Bile canaliculi periperal bile ductules(,Herings,),interlobular bile duct,Left&right hepatic ducts,Common hepatic duct,Common bile duct,Duodenum papilla,Cystic duct,Gall bladder,Biliary Passages,Classification of Lobules,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 boundar
消化腺（全英文）課件
