Gastrointestinal tract II. Histology and embryology Digestive tube Esophagus Ventricle - gaster Small intestine Large intestine Rectum Anus Esophagus stratified squamous nonkeratinising epithelium lamina propria mucosae distally esophageal cardial glands in submucosis mucinous glands - gl. oesophagicae proximally skeletal musculature adventitia serosa only in short abdominal part Slide Esophagus HE Gaster tunica mucosa areae gastricae foveolae gastricae simple columnar epi - mucous production lamina propria mucosae gastrical glands, lymphatic follicles tunica muscularis inner - fibrae obliquae medial - circular - m. sphincter pylori outer - longitudinal Tunica mucosa of gaster gastric pits deeper in pyloric part glands enter these pits gl. cardiacae - deep gl. gastricae propriae gl. pyloricae - shallow Gastric cells main cells- pepsinogen, lipase parietal cells- HCl, intrinsic factor abundant intracellular channels mucinous cells mucous enteroendocrine cells - gastrin, somatostatin undiferentiated cells - mitotically active Synthesis of HCl in parietal cells Cl - - from plasma H + - from H 2 CO 3 by carboanhydrase from CO 2 and H 2 O Slide Cardia of gaster HE Slide Fundus of gaster HE Intestinum tenue (= small intestine) duodenum jejunum ileum mesenterium - radix mesenterii plicae circulares, villi intestinales Tunica mucosa of small int. plicae circulares (Kerkringi) villi Crypts of Lieberkhn simple columnar epithelium lamina propria mucosae vessels, smooth muscles, lymph. foll. Cells of small int. mucosa enterocytes - resorption microvilli, interdigitations, lipid droplets goblet cells mucus production Paneth cells lysozym production endocrine cells - 12 types cholecystokinin, sekretin M-cells - over Peyers plates (later) undiferentiated cells Villi digit- to leaf-formed elements about 10times surface enlargement surface enterocytes, goblet cells smooth muscle skeleton lot of capillaries lymphatic, so called lacteal vessels Other layers of small int. wall Tela submucosa in duodenum glands of Brunner tuboalveolar mucinous alkalic secretion mainly in ileum Peyers plates acumulation of lymphatic tissue other layer correnspond to standard form of git tube Slide Pylorus duodenum HE Slide Duodenum HE Slide Small intestine HE Mucosa of large intestine no folds and villi crypts of Lieberkhn are deeper enterocytes less of microvilli goblet cells are numerous Paneth cells are missing endocrine cells are present Other layers of large intestine wall tunica muscularis externa inner circular - haustrations outer longitudinal reduced to taenie coli tunica serosa appendices epiploicae adipous tissue Slide Colon HE Appendix vermiformis Paneth cells are present lamina propria mucosae fulfilled with lymphatic tissue = noduli lymphoidei aggregati (tonsilla abdominalis) longitudinal musculature surrounds it completely no taenie Slide Appendix vermiformis HE Intestinum rectum pars pelvina plicae transversales recti - semilunar contains circular muscle layer canalis analis zona haemorrhoidalis - m. sphincter ani int. columnae anales (6-10) change of epithelium stratified squamous nonkeratinising anal plexus cavernous body zona cutanea keratinising epithelium glandulae circumanales (sweat and apocrine)