A secreção gástrica

1. A secreção gástrica extraído de: Vander, Sherman & Luciano, 2002 – WEBsite original: http://www.biocourse.com/mhhe/bcc/domains/quad/topic.xsp?id=000270

2. Veja mais em: http://mcb.berkeley.edu/courses/mcb136/topic/Gastrointestinal/Secretion_in_GI-Tract/

3. células mucosas SECREÇÕES EXÓCRINAS muco e HCO3- células principais pepsinogênio células parietais HCl e Fator Intrínseco http://anatomy.iupui.edu/courses/histo_D502/D502f03/f03_labs/Lab11/Lab11f03.html

4. Veja mais em: http://mcb.berkeley.edu/courses/mcb136/topic/Gastrointestinal/Secretion_in_GI-Tract/

5. Veja mais em: http://mcb.berkeley.edu/courses/mcb136/topic/Gastrointestinal/Secretion_in_GI-Tract/

6. Interações das secreções gástricas mucous extraído de: Vander, Sherman & Luciano, 2002 – WEBsite original: http://www.biocourse.com/mhhe/bcc/domains/quad/topic.xsp?id=000270

7. Proteção mucosa camada mucosa (0,2mm)   secreção de muco e HCO3- pelas células epiteliais e mucosas  fluxo sangüíneo ACh (PS e SNE) The protection provided to the mucosal surface of the stomach by the bicarbonate-containing mucus layer is known as the gastric mucosal barrier. In man, the mucus layer is about 0.2 mm thick. Buffering by the bicarbonate-rich secretions of the surface epithelial cells and the restraint to convective mixing caused by the high viscosity of the mucus layer allow the pH at the cell surface to remain near 7, whereas the pH in the gastric juice in the lumen is 1 to 2. COX1: atividade ciclooxigenase da PGH2-sintase). Berne et al., 2004 e outros: http://meds.queensu.ca/medicine/physiol/undergrad/phase2/phase2e/Ph2acid.htm

8. Mecanismos intracelulares de secreção ácida gástrica (célula parietal) extraído de: Vander, Sherman & Luciano, 2002 – WEBsite original: http://www.biocourse.com/mhhe/bcc/domains/quad/topic.xsp?id=000270

9. Regulação da secreção ácida gástrica Model for the regulation of gastric acid secretion. Shown are a parietal cell, an ECL cell, a D cell, and many of the important regulators of acid secretion. Parietal cells are stimulated by three main agonists: gastrin, histamine, and ACh. Gastrin binds to CCKB (gastrin/cholecystokinin-B)receptors on the parietal cell to evoke an increase in intracellular calcium; histamine binds to H2 receptors, which primarily signal through increased cAMP; ACh binds to M3 receptors to stimulate an increase in intracellular calcium. Parietal cell stimulation results in movement of H+/K+-ATPase pumps to the apical membrane to secrete acid. Histamine is released from ECL cells in response to gastrin stimulation as well as neuronal stimulation via PACAP (pituitary adenylate cyclase-activating polypeptide). Somatostatin (Sst) released from D cells inhibits acid secretion by reducing ECL cell histamine release, blocking gastrin release, and directly inhibiting parietal cell acid secretion. Annual Review of Physiology March 2003, Vol. 65, pp. 383-400 Samuelson and Hinkle, 2003

10. Regulação da secreção ácida gástrica e ações de drogas anti-ácidas: Olbe, Carlsson & Lindberg, 2003. Nature Reviews Drug Discovery 2, 132-139 (2003) http://www.nature.com/cgi-taf/DynaPage.taf?file=/nrd/journal/v2/n2/full/nrd1010_r.html

11. Regulação da secreção ácida gástrica na fase cefálica http://arbl.cvmbs.colostate.edu/hbooks/pathphys/digestion/stomach/index.html

12. Regulação da secreção ácida gástrica na fase gástrica http://arbl.cvmbs.colostate.edu/hbooks/pathphys/digestion/stomach/index.html

14. SECREÇÕES EXÓCRINAS PANCREÁTICA E HEPÁTICA http://www.nlm.nih.gov/medlineplus/ency/imagepages/1090.htm

15. VOLUME SECRETADO PELO PÂNCREAS NO INTESTINO DELGADO: 1,5 L/DIA ?

16. Principais tipos celulares encontrados no pâncreas Ilhotas de Langerhans hormônios: insulina (cél. β), glucagon (cél. α), somatostatina (cél. δ) e polipeptídeo pancreático (cél. θ) enzimas digestivas (proteases, amilase e lipases) secreção hidro-eletrolítica

17. HISTOLOGIA DO PÂNCREAS PORÇÃO EXÓCRINA enzimas e secreção hidroeletrolítica http://www.gastroslides.org/main/browse_deck.asp?tpc=6&mxpg=390&pg=2241#image PORÇÃO ENDÓCRINA (hormônios: glucagon, insulina, somatostatina e polipeptídeo pancreático) ilhota (células beta: insulina) ilhota (células alfa: glucagon) ácinos e ilhota de Langerhans http://www.udel.edu/Biology/Wags/histopage/histopage.htm

18. AS SECREÇÕES EXÓCRINAS PANCREÁTICAS: água e eletrólitos The relationships and major features of the units of the exocrine pancreas. The pancreatic acinar cells of the acinus have prominently stained zymogen granules in the apical area of the cell.  The connecting ductule does not contain zymogen granules. The blue cell in the cartoon depicts the centroacinar cell at the border between the acinus and ductule. The centroacinar cell functions similarly to the duct cell. The major secretory products of the acinus are digestive proenzymes and enzymes with lesser amounts of water and ions. The major secretory products of the duct are water and ions. http://www.gastroslides.org/main/browse_deck.asp?tpc=6&mxpg=390&pg=2243#image

19. AS SECREÇÕES EXÓCRINAS PANCREÁTICAS: água e eletrólitos The relationships and major features of the units of the exocrine pancreas. The pancreatic acinar cells of the acinus have prominently stained zymogen granules in the apical area of the cell.  The connecting ductule does not contain zymogen granules. The blue cell in the cartoon depicts the centroacinar cell at the border between the acinus and ductule. The centroacinar cell functions similarly to the duct cell. The major secretory products of the acinus are digestive proenzymes and enzymes with lesser amounts of water and ions. The major secretory products of the duct are water and ions. http://www.gastroslides.org/main/browse_deck.asp?tpc=6&mxpg=390&pg=2243#image

20. Importância da secreção hidroeletrolítica pancreática, rica em HCO3-, Na+ e água na digestão NaHCO3 + HCl  NaCl + H2O + CO2 (reabsorção) Neutralization of gastric acid delivered to the duodenum is necessary for optimal digestion and absorption of a meal. Several mechanisms that are not shown are involved in the neutralization process. First, the meal provides buffers from digestion of protein and triglycerides. That is, the peptides and fatty acid products act as pH buffers. Another neutralization process is absorption of hydrogen ion by the duodenal mucosa. Finally, the pancreas, biliary system and duodenal mucosa secrete bicarbonate into the duodenal lumen for neutralization. http://www.gastroslides.org/main/browse_deck.asp?tpc=6&mxpg=390&pg=2287#image

21. AS SECREÇÕES EXÓCRINAS PANCREÁTICAS: ENZIMAS The relationships and major features of the units of the exocrine pancreas. The pancreatic acinar cells of the acinus have prominently stained zymogen granules in the apical area of the cell.  The connecting ductule does not contain zymogen granules. The blue cell in the cartoon depicts the centroacinar cell at the border between the acinus and ductule. The centroacinar cell functions similarly to the duct cell. The major secretory products of the acinus are digestive proenzymes and enzymes with lesser amounts of water and ions. The major secretory products of the duct are water and ions. http://www.gastroslides.org/main/browse_deck.asp?tpc=6&mxpg=390&pg=2243#image

22. AS SECREÇÕES EXÓCRINAS PANCREÁTICAS: enzimas lipase a-Amylase (no activation needed) (Enterokinase) secreted by duodenal epithelium (from duodenal epithelial cells) http://mcb.berkeley.edu/courses/mcb136/topic/Gastrointestinal

23. AS SECREÇÕES EXÓCRINAS PANCREÁTICAS: enzimas lipase a-Amylase (no activation needed) (Enterokinase) secreted by duodenal epithelium (from duodenal epithelial cells) http://mcb.berkeley.edu/courses/mcb136/topic/Gastrointestinal

24. Relative amounts (by weight) of the different classes of pancreatic digestive enzymes. Proteases are the most abundant class of enzymes. http://www.gastroslides.org/main/browse_deck.asp?tpc=6&mxpg=390&pg=2273#image

25. AS SECREÇÕES EXÓCRINAS PANCREÁTICAS: enzimas lipase a-Amylase (no activation needed) (Enterokinase) secreted by duodenal epithelium (from duodenal epithelial cells) http://mcb.berkeley.edu/courses/mcb136/topic/Gastrointestinal

26. A secreção serosa pancreática: lipase pancreática Lipase pancreática

27. A secreção serosa pancreática: alfa-amilase Amilopectina (amido) da batata OBS: reparou que é a mesma ação da alfa-amilase salivar?

28. A secreção serosa pancreática: a ativação das pró-proteases pancreáticas no intestino delgado pela enteroquinase (da borda-em-escova) extraído de: Vander, Sherman & Luciano, 2002 – WEBsite original: http://www.biocourse.com/mhhe/bcc/domains/quad/topic.xsp?id=000270

29. A secreção serosa pancreática: a ativação das pró-proteases pancreáticas no intestino delgado pela enteroquinase (da borda-em-escova)

30. AS SECREÇÕES EXÓCRINAS PANCREÁTICAS

31. REGULAÇÃO DA SECREÇÃO EXÓCRINA PANCREÁTICA estimulação hormonal pancreática A presença de gordura e de ácido no duodeno estimula a secreção endócrina intestinal das células endócrinas “S” e “I”. As céls. “S” secretam a SECRETINA que estimula a secreção hidro-eletrolítica dos ductos pancreáticos

32. A REGULAÇÃO DA SECREÇÃO DOS DUCTOS PELA SECRETINA This image shows the stimulants for release of CCK from I cells and secretin release from S cells. Of note, the I cells and S cells “taste” the specific stimulants in the lumen of the gut to activate release of the hormones. The released CCK can mediate pancreatic secretion by either activating vagal sensory afferents that results in stimulation of pancreatic acinar cell secretion though a vago-vagal reflex involving the CNS or through the circulation (i.e. hormonal action). Secretin also acts through neural (not shown) and hormonal pathways on the pancreas stimulating secretion from both ductal cells and acinar cells. http://www.gastroslides.org/main/browse_deck.asp?tpc=2&mxpg=390&pg=1842#image

33. REGULAÇÃO DA SECREÇÃO EXÓCRINA PANCREÁTICA estimulação hormonal pancreática A presença de gordura e de ácido no duodeno estimula a secreção endócrina intestinal das células endócrinas “S” e “I”. As céls. “I” secretam a CCKque estimula a secreção serosa dos ácinos pancreáticos

34. A REGULAÇÃO DA SECREÇÃO DOS DUCTOS PELA CCK This image shows the stimulants for release of CCK from I cells and secretin release from S cells. Of note, the I cells and S cells “taste” the specific stimulants in the lumen of the gut to activate release of the hormones. The released CCK can mediate pancreatic secretion by either activating vagal sensory afferents that results in stimulation of pancreatic acinar cell secretion though a vago-vagal reflex involving the CNS or through the circulation (i.e. hormonal action). Secretin also acts through neural (not shown) and hormonal pathways on the pancreas stimulating secretion from both ductal cells and acinar cells. http://www.gastroslides.org/main/browse_deck.asp?tpc=2&mxpg=390&pg=1842#image

35. Regulação das secreção exócrina pancéática (ductos e ácinos) pelos hormônios intestinais http://arbl.cvmbs.colostate.edu/hbooks/pathphys/digestion/pancreas/control.html

36. The graphic in this image depicts the neurotransmission systems and neurotransmitters involved in regulating acinar and ductal secretion. The blue cell is called a centroacinar cell. These cells have characteristics more similar to ductal cells although their exact function is not known. Vagal efferents activate neurons in the intrapancreatic ganglia. Neurons from the ganglia then have processes that are in proximity to the parenchymal cells. These processes release the neurotransmitters, acetylcholine (Ach), gastrin releasing peptide (GRP) and vasoactive intestinal polypeptide (VIP) when their neurons are activated. Ach causes secretion from both acinar cells and ducts while all three neurotransmitters can cause secretion from acinar cells. http://www.gastroslides.org/main/browse_deck.asp?tpc=2&mxpg=390&pg=1842#image

37. RELEVÂNCIA CLÍNICA DE TAIS CONHECIMENTOS inseticidas organofosforados toxinas de escorpiões Exposição a inseticidas organofosforados (inibidores da acetilcolinesterase) ou toxinas específicas de escorpiões causam um aumento nos níveis de liberação de acetilcolina nas terminações nervosas, podendo causar pancreatite. A picada do escorpião Tityusserrulatus também tem sido causa de pancreatite. (G. Robles-Diaz, Mexico). http://www.gastroslides.org/main/browse_deck.asp?tpc=6&mxpg=390&pg=2317#image

38. A secreção exócrina hepática http://www.nlm.nih.gov/medlineplus/ency/imagepages/1090.htm

40. A secreção exócrina hepática: a bile Bile is a digestive fluid secreted by the liver and stored in the gallbladder which normally is released into the duodenum portion of the small intestine through the sphincter of Oddi. Bile, released after a meal containing fats, aids in absorption and digestion of the fat. http://www.nlm.nih.gov/medlineplus/ency/imagepages/1090.htm

41. Veja mais em: http://mcb.berkeley.edu/courses/mcb136/topic/Gastrointestinal/Secretion_in_GI-Tract/

42. Função digestiva da bile: sais biliares extraído de: Vander, Sherman & Luciano, 2002 – WEBsite original: http://www.biocourse.com/mhhe/bcc/domains/quad/topic.xsp?id=000270

43. Sais biliares e a emulsificação das gorduras extraído de: Vander, Sherman & Luciano, 2002 – WEBsite original: http://www.biocourse.com/mhhe/bcc/domains/quad/topic.xsp?id=000270

44. Sais biliares e a emulsificação das gorduras: a formação das micelas para a digestão pela lipase pancreática MICELA extraído de: Vander, Sherman & Luciano, 2002 – WEBsite original: http://www.biocourse.com/mhhe/bcc/domains/quad/topic.xsp?id=000270

45. Resumo da emulsificação, digestão e absorção de gordura extraído de: Vander, Sherman & Luciano, 2002 – WEBsite original: http://www.biocourse.com/mhhe/bcc/domains/quad/topic.xsp?id=000270

46. A circulação êntero-hepática dos sais biliares extraído de: Vander, Sherman & Luciano, 2002 – WEBsite original: http://www.biocourse.com/mhhe/bcc/domains/quad/topic.xsp?id=000270

47. REGULAÇÃO DA SECREÇÃO BILIAR Produção de bile+circulação êntero-hepática dos sais biliares e esvaziamento da vesícula biliar e relaxamento de Oddi pela CCK ? ? extraído de: Vander, Sherman & Luciano, 2002 – WEBsite original: http://www.biocourse.com/mhhe/bcc/domains/quad/topic.xsp?id=000270

48. A secreção exócrina intestinal: mucosa e hidroeletrolítica

49. Enzimas do intestino delgado: enzimas da borda-em-escova (constitucionais) para a digestão final de proteínas e carbohidratos extraído de: Vander, Sherman & Luciano, 2002 – WEBsite original: http://www.biocourse.com/mhhe/bcc/domains/quad/topic.xsp?id=000270

50. Enzimas do intestino delgado: enzimas da borda-em-escova (constitucionais) para a digestão final de proteínas e carbohidratos