Digestive glandsHongyaSunYangzhou University
1 Digestive glands Hongya Sun Yangzhou University
Digestive glandsOBJECTIVESThis chaptershould helpyouto:Comparemucousandserous secretory cellsinterms oftheirstructure,stainingproperties,andsecretoryproductsCompare the 3 major salivary gland types in terms ofcontent and distribution of serous and mucous cellsDescribethe division.structure andfunction ofthepancreasDescribetheboundaries andcontentsoftheclassicliverlobule,theportal space,andthehepaticacinusandunderstandtheliverfunctionsRelatethecomplexultrastructureofthehepatocytetoitsmany functions.2
2 OBJECTIVES This chapter should help you to: v Compare mucous and serous secretory cells in terms of their structure, staining properties, and secretory products. v Compare the 3 major salivary gland types in terms of content and distribution of serous and mucous cells. v Describe the division, structure and function of the pancreas. v Describe the boundaries and contents of the classic liver lobule, the portal space, and the hepatic acinus and understand the liver functions. v Relate the complex ultrastructure of the hepatocyte to its many functions. Digestive glands
GENERALDESCRIPTIONComponents ofdigestiveglands General features of digestiveglands
3 GENERAL DESCRIPTION Components of digestive glands General features of digestive glands
Componentsof digestiveglandssmall digestiveglands:--found within the wall of various regions of thedigestivetract--include: the esophageal glands, gastric glands,and intestinalglands,etc:large digestive glands:(accessory digestive glands--located outsidethedigestivetract-have ducts which open into the digestive tract--include:I.Salivaryglands(threepairs)I.PancreasIII. LiverIV.Gallbladder
4 Components of digestive glands v small digestive glands: -found within the wall of various regions of the digestive tract -include: the esophageal glands, gastric glands, and intestinal glands,etc. v large digestive glands: (accessory digestive glands) -located outside the digestive tract -have ducts which open into the digestive tract -include: Ⅰ. Salivary glands (three pairs) Ⅱ. Pancreas Ⅲ. Liver Ⅳ. Gallbladder
Tongue-ParotidglandSublingual glandSalivaryMouth (oral cavity)SubmandibularglandsglandPharynxEsophagusStomachPancreas(Spleen)LiverGallbladderTransversecolonDescendingcolonDuodenumSmallJejunumAscendingcolonintestine-LargelleumCecumintestineSigmoidcolonRectumVermiformappendix5AnalcanalAnus
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GeneralfeaturesofdigestiveglandsParenchyma-include:acini/gland cells and ducts- is the functional portion of an organ, as distinguishedfromthesupportingtissueMesenchyme(Stroma)- means the connective tissue-isthesupportandframeworkoftheseglands(capsule,connectivetissueinside)6
6 General features of digestive glands v Parenchyma - include: acini / gland cells and ducts - is the functional portion of an organ, as distinguished from the supporting tissue v Mesenchyme (Stroma) - means the connective tissue - is the support and framework of these glands (capsule, connective tissue inside)
I . Salivary glands
7 Ⅰ. Salivary glands
summaryA.The main functions of salivary glandstosecretesaliva--towetand lubricatetheoral mucosaandtheingestedfood--toinitiatethe digestionof carbohydratesand lipids-- to secrete germicidal substances (such as IgA,lysozyme)andlactoferrin--The saliva alsohasaveryimportant bufferingfunction and forms a protectivepellicleontheteethby means of calcium-binding proline-rich salivaryproteins8
8 A. The main functions of salivary glands to secrete saliva - to wet and lubricate the oral mucosa and the ingested food - to initiate the digestion of carbohydrates and lipids - to secrete germicidal substances (such as IgA, lysozyme) and lactoferrin - The saliva also has a very important buffering function and forms a protective pellicle on the teeth by means of calcium- binding proline-rich salivary proteins summary
B.Classification of salivary glandsThere arethree pairs of salivary glandsParotid gland1.parotidglandsigu2.submandibularglandsTeeth3.sublingualglandsDuctsofsublingualglandfunction:Parotidduct(Massetermuscle)FrenulumoftongueBody of mandible>tosecretesaliva(cut)SublingualSubmandibularglanddeSubmandibularglancMylohyoid
9 There are three pairs of salivary glands 1. parotid glands 2. submandibular glands 3. sublingual glands v function: to secrete saliva B. Classification of salivary glands
C.General structure of salivaryglands1.Secretory acinus:presents 2 types of secretory cells serous cells-- serous acinimucous cells--mucousacini(*both serous and mucous cells--mixed acini·the nonsecretory myoepithelia cellsE
10 1. Secretory acinus: presents 2 types of secretory cells serous cells- serous acini mucous cells- mucous acini (* both serous and mucous cells-mixed acini) the nonsecretory myoepithelia cells C. General structure of salivary glands