20070918胃腸道組織學(xué)

1、1Digestion & Nutrition2教學(xué)目標(biāo)及基本要求1. 掌握消化管的基本結(jié)構(gòu)。2. 了解口腔粘膜的結(jié)構(gòu)。3. 了解舌的結(jié)構(gòu)和牙的結(jié)構(gòu)。4. 掌握消化管各段的結(jié)構(gòu)特點(diǎn)及功能。5. 了解消化管的免疫功能。6. 了解消化管內(nèi)分泌功能。 3General structure of digestive tract mucosa epithelia lining: (stratified squamous or simple culumnar)lamina propria: LCT(vessel, nerve, gland, LT)muscularis mucosa: thin smooth

2、 macular muscularis: inner circular, outer longitudinal (skeletal or smooth muscular) adventitia：thin loose connective tissue (fibrosa or serosa) submucosasubmucosal nerve plexusgland(only in esophagus and duodenum)45mucous Lower surface：smoothDorsal surface：irregularmuscularis：mass of striated skel

3、etal muscularTaste budFiliform papillaeFungiform papillaeCircumvallate papillaeTONGUE6Filiform papillaeFungiform papillaeFoliate papillae7taste buds8epitheliumlamina propriaTunica muscularisFibrosaTunica mucosamuscularis mucosaestratified squamousTunica submucosa skeletal in upper 1/3rdmixed in midd

4、le 1/3rdsmooth in lower 1/3rdESOPHAGUS9Tunica submucosa with glandsEpithelium (non keratinized stratified squamous)10Junction of esophagus and cardia ESOPHAGUS11 mucosa: epithelium, lamina propria, mucularis mucosae gastric pit, gastric gland muscularis: smooth muscle serosa: mesothelium submucosain

5、ner oblique, middle circular, outer longitudinalSTOMACH1213STOMACH: DivisionsHistology shows corpus & fundus to be the same = “fundic stomach”CorpusPylorusCardiaFundus14 surface mucous cellgastric pit-surface epithelia extent into lamina proprialamina propriaCardiac glandFundic glandPylorus gland15F

6、undic gland ： Chief Parietal cell Mucous neck cell Enteroendocrine cell Gastric stem cell16 chief cell：zymogenic cellLocation: predominate in the lower of gastric glandLM: small than parietal cell, basophilic cytoplasmEM: have the characteristics of a protein synthesizingFunction: secreting pepsinog

7、en which activated in acidic environment into pepsin.17 parietal cell ：oxyntic cellLocation: mainly in the upper half of gastric glandLM: round or pyramidal morphology and intensely eosinophilic cytoplasmEM: intracellular canaliculus and abundance of mitochondriaFunction: secreting HCl and intrinsic

8、 factor 1819Mucous neck cells present in cluster or as single cells between parietal cells in the necks of gastric glands.Gastric stem cell few in number, these cells can differentiate into mucous neck, parietal, chief and enteroendocrin cellsSTOMACH: Cell typesChief/Peptic cellEnteroendocrine cell

9、small, pale, few; granules are located basally for release into the lamina propriaparietal cell/oxyntic cell20Cardiac regionGland is often coiled and has a large lumenSecrete mucus and lysozyme Junction of esophagus and cardia 21Pylorus region Glands have long pits and short coiling Secrete mucus an

10、d enzyme lysozymeG cells secret gastrin, D cells secret somatostatin22SMALL INTESTINE consist of duodenum, jejunum and ileum the main site of food digestion, metabolite absorption, and endocretion2324duodenumjejunumplicae circulares25intestinal villiCentral lacteal 26Mucous membraneMicrocilli: cylin

11、drical protrusion of the apical cytoplasm and the cell membraneIntestinal villi: out growths of the mucosa (epitheliam plus lamina propria) into the lumen Plicae circulares: the semilunar or spiral projection of mucosa and submucosaFunction: increasing the area of contact between the intestinal surf

12、ace and food.27striated border(microvilli)absorption cellgoblet cellIntestinal villus28Intestine glandAbsorption cell: tall columnar cells with striated border(microvilli)Goblet cell: less in the duodenum and increase in numbers the ileum is approached. Paneth cell: in the basal portion of the gland

13、, synthesize a complex of protein and polysaccharide Enteroendocrine cell: secret hormoneUndifferentiated cell: gastric stem cells 29paneth cellpaneth cellgoblet cellgoblet cellabsorption cellabsorption cell30Characteristics of different small intestine： Decreased plicae circulares Increased goblet

14、cells in mucous Increased lymphoid tissue in lamina propria and submucous (from duodenum to ileum)31duodenum32ileum33 Consists of rectum, colon and appendix Long intestine glands, no villi Great abundance of goblet and absorptive cells, no Panthe cells The lamina propria is rich in lymphoid cells an

15、d nodulesLARGE INTESTINEFunction: absorption of water and formation of the fecal mass plus production of mucus34large intestine35junction of rectum and anus36 an evagination of cecum with small, narrow and irregular lumen abundance lymphoid follicles in its wall fewer and shorter intestinal glands c

16、ompared with other section of large intestineAPPENDIX37appendix38constitute diffused lymphoid cellssolitary lymphoid noduleaggregated lymphoid noduleM cell(microfold cell)lymphoid tissue of the gastrointestinal tract39M celllocation: overlaying the lymphoid follicles of Peyers patchesmorphology: num

17、erous membrane invaginations forming pit at their apical and lateral surfaces and intraepithelial lymphocytes are contained in itfunction：endocytose antigens and transport them to lymphoid cells, so that initiate immune responses4041lymphoid tissue of ileum42lymphoid tissue of appendix43 a serious of widely distributed cells with characteristics of the diffuse neuroendocrine system open type: cell presents microvilli and contacts the lumen closed type: cell apex is covered by other epithelial cells function: modulate the digestive ac