Henriette Lecture Notes - Digestion 2 PDF

chywe-food bous passed on by stomach , interdigestive Bile secretion liver-common lepatic duct state oddi splinter closed : -...

chywe-food bous passed on by stomach , interdigestive Bile secretion liver-common lepatic duct state oddi splinter closed : - - through bile stored oddi in sphincter-duodeu gall bradder euters duodem s activation release fallbladdercontraine Fed state - Hormone : Cybe bile release Amount: 0.6-1.2 l/d - an oddi Composition: sphincter v  Water (liver – 98%, gallbladder – 92%)  Bile acid (cholic acid and chenodeoxycholic) salts, in Liver ↳ conjugated  Bilirubin,  Cholesterol, ↳ 444 Cholestera - Ihot Cristilization - watersemble gall stores  Phospholipids (Lecitin), > - helps to dissolve cholester  Inorganic substances (Na, K, Ca, Cl, bicarbonates) duodennu ↳ aeid in veutrolich gastric  Functions of the bile  Fat emulsification,  Activates lipase, > - Co-lipase helps for lipase to attach  Stimulates fat absorption,  Stimulates absorption of fat soluble vitamins, ↳ incorporated in Micelles  Inactivates pepsin, > - alkaline medium of bile inactivates pepsin  Stimulates peristalsis in the small intestine, > - untrients lixed with infestival juces and delivered further  Bactericidal,> - production of secretary immuneglobulives ?  Excretory (drugs, toxins). - excretion of substances bound to albulius & with long arch molecular ↳ can't be weight excreted in wine hydrophilic hydrophobic Fat globule Bile acid salt Micelle Bile secretion Bile secretion is stimulated by:  Parasympathetic nervous system, Vagus N 3 -. blade contraction oddi splincter relaxation  Cholecystokinin, gall , &  Secretin,> - 4 bile secretion in liver (4Ho HOs secretion , in hepatic bile)  Bile salts that are reabsorbed in small intestines. Enterohepatic circulation of bile salts portal vein facilitatedsich passive diffusion passiertension Na+ Nat bile salt co-transport , E apical Surface 5% ↑ terminalpart ilemm  Pancreatic juice Amount ~ 0.5 – 1 l/d Composition: Alkalive : reduces acidity in duodenne  Water 98.5%  Enzymes that break down all three macronutrients:  Proteins: Trypsinogentrypsin, activated by enterokinase in small S  producedin intestines, (duodemm) inactive form &  Chymotrypsinogenchymotrypsin, activated by trypsin activated in de  Carboxypeptidases, activated by trypsin.  Carbohydrates -  amylase, re helps attach lipase to Micella  Lipids – lipase (+colipase), cholesterol esterase, phospholipase ↳ for cholester esters ↳ lipids ↳ for phospholipids  Inorganic substances (Na, K, Ca, Cl, bicarbonates). L neutralize acidic medium in duodentum  when stimulated cell Stimulation a ductul ↑ G-uptake into ductal cells Acinar IHCO3- & Na+ Cl- cells Lenzywe I ATP production U--channel K+ Cl- Na+ HCO3- H+ Ductal H2CO3 cells ↳ elektrolyte Secretion CA H2O + CO2 Na+ isotonic > - duct is water permeable H2O L. Costanzo Physiology 4th ed Secretion of pancreatic juice Secretion is stimulated by:  Parasympathetic nervous system, N. Vagus > - ACH-My- paucreatic secreation  Cholecystokinin, > - affects aciner cell + enzyme secretion into pancreatic juce  Secretin. -electrolyte secretion from ductal cells into pancreatic juce Digestion in the small intestine  Secretion of the intestinal juice  Motility  Absorption  Intestinal juice  Amount: 1 – 3 l/d wainly Ho  Composition:  Enzymes – attached to epithelial cells and provide digestion on brush border:  Peptidases, Icarboxypepticases , amihopeptidases , endo peptidases  Disaccharidases, IMaltase , Sucrase , Lactase)  Intestinal lipase on brush boarder ↳ digests lipids  Mucin, ↳ protects wall , ↑ stipeiness  Inorganic substances (Na, K, Ca, Cl, bicarbonates). ↳ neutralize acidity  Secretion is stimulated by:  Submucous plexus, !  Parasympathetic nervous system,  Secretin, ↑electrolyte > - Secretion LHO , HC03]  Cholecystokinin. > - evry we production Types of motility E V & & ~ > ~ in small intestine [ > [  Segmentation, ↳ lixing dyme with intestival , pancreatic > - Circular musche contraction juce , bile hiv small intestine  Peristalsis, longitudinal ↳ > - > - > - circular muscle contraction circular musche relaxation muscle in in in direction of cad caudad direction audad direction more syme forward  Tonic sphincter contractions. ↳ is dependend on pressure : opening > - large open Psmall : intestine > Plange intestive Chyme intestive closed : Pomall intestive < Plage infestive > - Motility is regulated by: tract leve of digestive  Myenteric plexus, ↳ Wall of small intestive  Parasympathetic nervous system, stimulate  Cholecystokinin,  Secretin – decreases. ↳ acidic content = ↑ Secretin - ↓ motility - neutralized before it moves further Berne and Levy Physiology 7th ed.  Absorption in small intestines Absorption due to large surface area (~250 m2): 5-6m increas of surface crea  Circular folds (~ 3x),  Intestinal villi (+10x)  Microvilli (+ 20x) Absorption in small intestines > - major absorption : small intestive winer absorption cral cavity - :  Breakdown of substances is complete, and monomers are transported near the wall: > - into interstitial space-blood · lymph  Proteins amino acids,  Carbohydrates monosaccharides,  Lipids free fatty acids, monoglycerides. Digestion and absorption of charbohydrates  Polysaccharides Digestion and (starch, glycogen) Saliva absorption of Amylase Glucosidase carbohydrates Pancreatic juice Amylase Brush border in small intestine: Maltase Lactase Sucrase glucose or intestinal lumen- Na+ galactose fructose GLUT - fascilitated diffusion SGLT 5 - -Nat , gucose symport wembran apical Na+ basolateral surface - GLUT ATP 2 ~ fascilitated diffusion K+  Gastric juice: Proteins Gastric juice: Digestion and denaturates HCl quarticary proteins Pepsin > - absorption of proteins structure Pancreatic juice HCL Pepsikogen Pepsin (active) Trypsin > entherokinase Chymotrypsin < Trypsin(active Trypsin Carboxypeptidases < Chymotrypsinactive Brush border in small intestine: Trypsin , Carboxypeptidaselactive Peptidases Amino acids Di- and tri- Oligopeptides peptides Na+ H+ Nat, amino acid symport - Symport M transcytosis - Na+ H+ 2 ATP fascilitated/ diffusion antiport K+  Triglycerides Saliva: Digestion and Lipase Im digestion( Gastric juice: tatscremet emulsified jet absorption of fats Bile: Lipase 1 digestion) Bile salts small intestive Pancreatic juice: Phospholipids provide emulsification Lipase (+colipase) Phospholipase Cholesterol esterase Brush border in small intestine: Lipases Monoglycerides Free fatty acids RER SER chylomicion Monoglyceride Free fatty acid Lymph vessel Cholesterol toobig Apoprotein  Absorption of water and electrolytes ↳ 6-8) 2-31 gastrointestival juces produced fluids though drinking/eating I has > - to be reabsabe YL absorbed in large intestive ↳ 5-7tLabsorbed in small intestive CFTR - cystic fibrosis transmembrane conductance regulator ACH,VIP, Cholera toxin PGE2,Histamin D3 vitamin ↑ Nat in wer - Hediarre a ↓ U - Hose thick mucous increases number of dannel + K+, Ca2+, Na+ - hu - Cl- + Ca2+ AA Na+ Na+ Gal Na+ + +UmH2O Cl- fascilitated space diffusion SGLT paracellular CFTR H+ HCO3- Cl- calbindin Ca2+ + Na+ ---- K+ Cl- Na+ K 2Cl- Ca2+ 11 ATP ( ATP K+ interstitial space sinda Na+  Digestion in large intestine  Secretion ↳ day enzymes > - large intestinal juce : 200 mI trolssie  Absorption of electrolytes and water,  Fermentation proteins and carbohydrates, > - by Bacterial enzymes  Synthesis of vitamins > - By Bacteria via sodium-short chain fatty acid transporters into couch epith.  Processing of fibers - convert to short-chain fatty acids by digestable intestinal bacteria that fuel epithelium of colon. ↳ hot > - By bacterial enzywes Types of motility:  Segmentation / haustration,  Peristalsis, Chyme  Antiperistalsis, ↳ moves content back and forth-4Ho > - save as direction paristalis , but opposite , electrolyte absorption  Tonic sphincter contractions, > - opens only during defication reflex Lanal splincter  Defecation. ↳ of rectuen > - through 5-segments of Spinal card aupting Defecation reflex Cortex & we feel need to go to bathroom Sensory tiber ↑ filled-4 impulse frequency - ↑ defication reflex Rectum ~ Stretch recepters Myenteric plexus + contraction of well inhibitery weiron parasympathatic relaxation internal sphiucto - - = internal sphincter (SM cells) + = ↳ autohonic IS external sphincter (skeletal) ↳ servatic NS Sacral-segment ↑ relaxation external sphincte inhibition = Portal blood flow Hepatic artery – 25% > - arteial bload Portal vein – 75% > - venous blood : for detoxification modification , in live - Hepatic and porfel blood mix Berne & Levy Physiology 7.ed  vera cave colaterals : veins that powr same blood goes directly into ↳ evel of rectum ↳ lbilical region ↳ Haemorrhoidal ↳ upper stomech , lower esophagus w e cirrosis : ↑ blood flow though collateral veius live ↓ tilteilg in > - car cause neurotoxisity collaterals M.Wong, R. W. Busuttil Surgery in Patients with Portal Hypertension Clin Liver Dis 23 (2019) 755–780 https://healthjade.net/portal-vein/ Liver blood flow Hepatic portal veil - sinusoidal capillaries > - entral vein - hepatic veins Hepatic cutery with Space of Disse > - spaces in sinuseid capillaries - substance exchange into rm > - substance uptake lepatolytes > - modification of substances secreation through bill canaliculi - gall bladder / duodemum > secreted back into space of Disse blood nessel ' blood vessels lymphatic vessels e ↑ A Berne & Levy Physiology 7.ed Liver functions  Bile secretion>galbladd -  Metabolic functions: - receives blood nutrieuts from gastrointestival tract with  Carbohydrate metabolism:  Glycogen synthesis Arom glucose) - for storage  Gluconeogenesis  Fat metabolism:  Fatty acid oxidation  Synthesis of fatty acids, lipoproteins, cholesterol, phospholipids  Conversion of carbohydrates into lipids  Protein metabolism  Plasma protein synthesis,  Non-essential amino acid synthesis  Deamination of amino acids, conversion of ammonia– urea production Liver functions stellate ↑ cells hydroxylation  Fat soluble vitamin metabolism and storage (A, D, K, E)  B12 vitamin storage synthesis> - for Love  Iron and copper storage ↳ Leuesynthesis ↳ eulymatic activity regulation  Detoxification:  Kupffer cells > - activate makrephages > - digest particles in blood stream  Cytochrome P450 > - substance inactivation loxidation reduction , , hydroxylation)  Conjugation  Excretion (bilirubin, drugs, heavy metals, toxins)  Clotting regulation:  Clotting factors synthesis  Heparin synthesis - clotting inhibits blood  Blood depot ↓ BP - liver BV constrict > - Blood volume - > ↑BP  Thermoregulation > - heat as side product of metabolic activities of live  Hormonal regulation > - > - inactivation , removal production of : Angiotensinger , Ds , Hermore precursors, Cholester