[Verse 1] Twenty feet of folded architecture, villi reaching like antennae to the sky Surface area of a tennis court concealed inside — don't ask me how, just ask me why Duodenum leads, iron and calcium report for duty, folate binds its carrier tight Proximal jejunum handles monosaccharides, SGLT-1 dragging glucose to the right Proteins cleaved by brush-border peptidases, dipeptides and amino acids flood the gate Fats emulsified by bile into micelles, fatty acids slip the membrane — can't wait Terminal ileum's got a specialist role — B12 needs intrinsic factor, that's the deal And bile acids recycled, ninety-five percent recaptured — enterohepatic wheel [Chorus] Assorbimento — dalla bocca fino al sangue Absorção total, cada nutriente que avance Duodenum iron, ileum bile and B-twelve claim MMC sweeps clean between the meals, three phases, cyclic flame Assorbimento — the gut remembers every name [Verse 2] Nine litres flood this tube each day — saliva, bile, pancreatic juice, the lot Seven thousand millilitres soaked back up before the colon gets its shot Sodium pulls the water, paracellular routes and channels lining every crypt Chloride secreted, sodium absorbed — electrochemical grip CCK drops from the I-cells when fat and protein hit the duodenal floor Secretin from the S-cells, bicarbonate surges through the pancreatic door GIP and GLP-one — incretin axis — glucose-dependent insulin release Metabolic surgery reroutes the meal, bypasses foregut, makes the incretins increase [Chorus] Assorbimento — dalla bocca fino al sangue Absorção total, cada nutriente que avance Duodenum iron, ileum bile and B-twelve claim MMC sweeps clean between the meals, three phases, cyclic flame Assorbimento — the gut remembers every name [Bridge] Migrating motor complex — motilin-driven housekeeper at phase three Thirty minutes of propulsive contractions clearing bacteria free Fed pattern interrupts it — segmentation scatters, mixes, slows the transit down Ileal brake — fat in the distal gut, GLP-one and PYY slow the proximal crown GALT in Peyer's patches, M-cells sampling luminal antigen all day Microbiome fermenting SCFA — butyrate fuels colonocytes, keeps inflammation at bay [Verse 3] Short bowel — quando resta poco intestino, every centimetre counts now Duodenum alone won't cut it — you need a hundred cm minimum somehow Ileocecal valve intact? You can survive on seventy-five, colonic salvage amplifies Without the valve you're writing prescriptions for parenteral nutrition supplies Adaptation spans two years — villous hyperplasia, crypts deepen, transit slows GLP-two from the L-cells drives that mucosal growth, that's how the remnant bowel grows Colon absorbs fluid and ferments carbohydrate when the ileum's gone A functional colon buys your patient months before the TPN's switched on
← 1 Gastric Physiology | 3 Colonic and Anorectal Physiology →