GIT - 3 General architecture of small and alrge intestine appendix vermiformis 1. Tunica mucosa: no villi, rare and shallow crypts - simple columnar epithelium, - lamina propria – reticular connective tissue, lymphatic follicles - lamina muscularis – thin, discontinuous. 2. Tela submucosa – loose collagen c.t. with adipocytes 3. Tunica muscularis externa – thin 4. Serosa. Intestinum crassum 3 parts: - caecum + appendix, - colon (ascendens, transversum, descendens, sigmoideum), - rectum + canalis analis. 1. Mucosa - crypts - simple columnar epithelium - l. propria – reticular c.t. - l. muscularis – smooth muscle 2. Submucosa 3. Muscularis externa 4. Serosa No villi Intestinum crassum circular longitudinal – taeniae coli (3x) Serosaappendices epiploicae adipose tissue Intestinum crassum Intestinum crassum Lieberkühn crypt lamina propria mucosae lamina muscularis mucosae Submucose Muscularis externa Enterocytes + goblet cells Intestinum crassum (HE) Intestinum crassum Rektum – ampulla + canalis analis Ampulla – like colon Canalis analis Plicae transversales (1, 2, 3) 5-10 columnae rectales + sinus et valvulae anales m. levator ani M sphincter ani: ext. int. 1 2 3 Local histology of anal canal Zona hemorhoidalis Zona intermedia Zona cutanea Mucosa Skin - simple columnar ep. - stratified squamous ep. - epidermis - lamina propria - lamina propria - dermis + adnexa - reticular c.t. (loose collagen c.t.) + pigment cells - lamina muscularis -- -- Submukóza + -- Muscualris externa: smooth smooth (m. sphincter int.) skeletal (m. sphincter ext.) Adventitia + -- Canalis analis zona cutanea zona zona intermedia hemorhoidalis Liver (hepar) • Connective tissue capsula fibrosa hepatis (Glissoni) + serosa • Liver parenchyma – cords of hepatocytes – define liver lobuli Lobulus venae centralis (hepatic, liver lobulus) • Polygonal • Vena centralis – in axis • Cords of hepatocytes arranged radially • Hepatic sinusoids • Bile capillaries „sheets“ (3D) – „cords“ (2D) of hepatocytes Lobulus venae centralis = Structural unit Jaterní buňka (hepatocyt) area periportalis (Glissoni) Portal triad (Glissoni): Interlobular Bile duct – 1 Vein – 2 Artery – 3 branches of portal vein and hepatic artery 1 2 3 Circulation in liver Portal acinus Sinusoids Vena centralis - AZAN Trias hepatis in area periportalis Vein Artery Bile duct Sinusoids • Modified blood capillaries – radially from periphery to v. centralis • Fenestrated wall • Endothelium and Kupfer cells • lamina basalis absent • Perisinusoidal space (Dissé) – between sinusoid wall and hepatocytes Intercellular bile duct (bile capilary)) Sinusoids – Kupffer cells Hepatocytes – glycogen (PAS) Bile ducts intrahepatic • Bile capilaries (ducts) • Canals of Hering • Interlobular ducts • Lobar ducts (ductus hepaticus dex. et sin.) extrahepatic • ductus hepaticus • ductus cysticus • ductus choledochus Gall bladder (vesica fellea) • mucosa – Folded – Simple columnar epithelium – lamina propria – Lamina muscularis absent • Submucosa – fibromuscular layer • Muscularis externa well developed • Dominant subserous connective tissue (subserosa) • Adventicia (liver) or serosa (free surface) Vesica fellea Tunica mucosa Tunica muscularis externa subserous c.t. lamina propria serosae + mesothelium Vesica fellea serosa Vesica fellea – folds of mucosa simple columnar epithelium lamina propria mucosae Pancreas • Connective tissue cover (capsula fibrosa, septa) • Parenchyma: exocrine: - serous acini (serous and centroacinar cells) - ducts: intercalated, intra- and interlobular, main (ductus pancreaticus major et accessorius) endocrine: islets of Langerhan(cells: A – glucagon, B – insulin, D – somatostatin, PP – pancreatic polypeptide) tubuloacinar gland, pancreatic juice /1.5 l/ is a clear alkaline fluid which contains the precursors of enzymes – trypsin, chymotrypsin, lipase, amylase.. Pancreatic acinus + intercalated duct Pancreas – exocrinne acinus Pancreas – exocrinne (Mallory) Pancreas – endocrine (HE) Pancreas – endocrine (HE) GIT - III Slides: 17. Intestinum crassum (HE) 18. Appendix (HE) 19. Anus(HE) 20. Hepar(HE) 21. Hepar (AZAN) 22. Vesica fellea (HE) 23. Pancreas (HE) Atlas EM: Bile duct (10)