組胚2012級(jí)臨床醫(yī)學(xué)消化管

1、第章消化管Digestive tract消化系統(tǒng)組成 消化管 消化腺消化系統(tǒng)功能 消化吸收 免疫 內(nèi)分泌消化管壁的一般結(jié)構(gòu)： 1 黏膜mucosa 上皮epithelium 固有層lamina propria黏膜肌層muscularis mucosa 2黏膜下層submucosa 食管腺和十二指腸腺 皺襞plica 3 肌層muscularis 內(nèi)環(huán)、外縱兩層 神經(jīng)叢 4 外膜adventitia 纖維膜fibrosa 漿膜serosa 食管esophagus 黏膜:未角化復(fù)層扁平上皮,黏液性腺泡,黏膜肌層為一層縱行平滑肌 黏膜下層:食管腺 肌層:內(nèi)環(huán)、外縱,骨骼肌向平滑肌過渡 外膜:纖維膜

2、胃 1黏膜：上皮為單層柱狀上皮,主要為表面黏液細(xì)胞surface mucous cell,參與黏液碳酸氫鹽屏障的生成.固有層含胃底腺、賁門腺和幽門腺;黏膜肌層為內(nèi)環(huán)外縱兩層. 胃小區(qū)gastric area,胃小凹gastric pit, 2黏膜下層:較致密結(jié)締組織 營養(yǎng)血管 淋巴管 神經(jīng)等 3 肌層:內(nèi)斜、中環(huán)、外縱三層 4 外膜:為漿膜 胃底腺fundic gland,或稱泌酸腺oxyntic gland 分部 峽、頸、底三部 細(xì)胞有主細(xì)胞、壁細(xì)胞、頸黏液細(xì)胞、干細(xì)胞和內(nèi)分泌細(xì)胞. 1 主細(xì)胞chief cell 又稱胃酶細(xì)胞zymogenic cell,柱狀,多集中于腺體底部,胞質(zhì)基部嗜

3、堿染色. 功能 分泌胃蛋白酶原pepsinogen2 壁細(xì)胞parietal cell（泌酸細(xì)胞oxyntic cell) 以胃底腺峽、頸部較多 胞質(zhì)嗜酸染色 電鏡結(jié)構(gòu) 細(xì)胞內(nèi)分泌小管intracellular secretory canaliculus、微管泡系統(tǒng)tubulovesicular system、線粒體 功能: 合成和分泌鹽酸 分泌內(nèi)因子intrinsic factor3 頸黏液細(xì)胞mucous neck cell 染色淡，分泌酸性黏液4 干細(xì)胞stem cell 可分化為其它的胃底腺細(xì)胞5 內(nèi)分泌細(xì)胞 ECL細(xì)胞 分泌組胺 D細(xì)胞 分泌生長抑素 小 腸 一黏膜 環(huán)行皺襞、腸絨毛

4、intestinal villus、小腸腺small intestinal gland 單層柱狀上皮覆蓋腸絨毛表面并構(gòu)成腸腺 腸腺細(xì)胞組成：吸收細(xì)胞absorptive cell、杯狀細(xì)胞goblet cell、潘氏細(xì)胞Paneth cell、干細(xì)胞、內(nèi)分泌細(xì)胞 固有層:腸腺,多種結(jié)締組織細(xì)胞,中央乳糜管,淋巴小結(jié). 黏膜肌層:內(nèi)環(huán)、外縱平滑肌.二 黏膜下層:在十二指腸段此層有腸腺三 肌層:內(nèi)環(huán)，外縱平滑肌四 外膜：主要為漿膜 大 腸Large intestine一黏膜：上皮為單層柱狀，細(xì)胞成份：吸收細(xì)胞、杯狀細(xì)胞（數(shù)量較小腸多），固有層有大量大腸腺和淋巴組織二黏膜下層：結(jié)構(gòu)同小腸三 肌層：內(nèi)

5、環(huán)、外縱 參與結(jié)腸袋（帶）的構(gòu)成四 外膜：漿膜或纖維膜 消化管的淋巴組織及其免疫功能 1 消化液的防御功能 2 淋巴組織和免疫細(xì)胞的免疫功能 3 微皺褶細(xì)胞microfold cell， M細(xì)胞 4 分泌型IgA secretory IgA sIgA 胃腸的內(nèi)分泌細(xì)胞 胃腸內(nèi)分泌細(xì)胞的特點(diǎn) 分散存在 種類多 總量大 所分泌的激素除調(diào)節(jié)消化管消化功能以外 也參與調(diào)節(jié)其它器官的生理活動(dòng) 細(xì)胞類型分開放型和封閉型 激素類型多為肽類或胺類。 作用方式 血循環(huán)、旁分泌The digestive tract extending from the esophagus to the large intesti

6、ne is made up of four concentric layers, exhibiting considerable regularity. Named in order from the lumen outward, these are the mucosa, submucosa, muscularis externa, and adventitia or serosa.The mucosa, or mucous membrane, has three components: superficial epithelium, lamina propria and musculari

7、s mucosa. The muscularis mucosa is subdivided into an inner circular and an outer longitudinal layer. Large accumulations of typical lymphatic tissues are often present in the stroma. The entire lamina propria of most segments of the gut is a major site of immunologic response. The mucosa projects i

8、nto the lumen as folds or villi. These invaginations and evaginations of the lining of the gut increase its effective surface area tremendously. The mucosa differs considerably from segment to segment of the alimentary tract in relation to the changing functional activity. Considerable emphasis will

9、 be placed in the following descriptions on the specialized mucosa cells involved in secretion and absorption. The submucosa is a connective tissue layer, often containing accumulations of lymphatic tissue as well as glands that extend from the mucosa. The muscularis externa contains at least two la

10、yers of muscle. The muscle is smooth in all parts except for the upper esophagus and the anal sphincter,where it is composed of skeletal muscle fibers. The muscle fibers of the inner layer are arranged in a circular manner while that of the outer layer are longitudinal. Contraction of the circular layer constricts the lumen whereas contraction of the longitudinal layer shortens the tube. The adventitia is made