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~/attachments/e4a3f972-1ada-4257-84ff-3fdfe8f6d3a9

intestinal absorption AND malabsorption

intestinal absorption physiology fat carbohydrate protein absorption Merck Manual

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mkdir -p "/tmp/workspace/git_absorption_qa/src" "/tmp/workspace/git_absorption_qa/output" && python - <<'PY' from PIL import Image from pathlib import Path for p in Path('/tmp/workspace/attachments/e4a3f972-1ada-4257-84ff-3fdfe8f6d3a9').glob('*.jpg'): im=Image.open(p) print(p.name, im.size) PY

python - <<'PY' from pathlib import Path p=Path('/tmp/workspace/git_absorption_qa/src/create_deck.py') p.write_text(r'''from pptx import Presentation from pptx.util import Inches, Pt from pptx.enum.text import PP_ALIGN, MSO_ANCHOR from pptx.enum.shapes import MSO_SHAPE from pptx.dml.color import RGBColor from pptx.enum.dml import MSO_THEME_COLOR from pathlib import Path OUT=Path('/tmp/workspace/git_absorption_qa/output/GIT_Absorption_and_Selective_Malabsorption_QA.pptx') prs=Presentation(); prs.slide_width=Inches(13.333); prs.slide_height=Inches(7.5) blank=prs.slide_layouts[6] NAVY=RGBColor(12,47,76); BLUE=RGBColor(16,112,156); TEAL=RGBColor(0,150,136); PALE=RGBColor(235,247,248); INK=RGBColor(30,43,52); MUTED=RGBColor(88,105,116); WHITE=RGBColor(255,255,255); GOLD=RGBColor(241,180,54); LIGHT=RGBColor(246,249,251) slides=[ ('Foundations of Absorption',[ ('What are the three stages of intestinal absorption?','Luminal phase: enzymatic digestion in the lumen. Mucosal phase: uptake across enterocytes and brush-border activity. Post-mucosal phase: transport from epithelial cells into blood or lymph.'), ('Where does most nutrient absorption occur?','In the proximal two-thirds of the small intestine, especially the jejunum more than the duodenum. The ileum is important for bile-acid and vitamin B12 absorption.'), ('Which small-intestinal features increase absorptive capacity?','Plicae circulares, villi, and the enterocyte brush border. Enterocytes renew continuously, roughly every 48-72 hours.')]), ('Small Intestine: Histology and Key Sites',[ ('What are the main cells and structures in villi and crypts?','Villi are lined by enterocytes with a brush border. Crypts of Lieberkühn contain Paneth cells, goblet cells, enteroendocrine cells, and renewing stem-cell populations.'), ('What do Paneth cells secrete?','Host-defense substances including alpha-defensins, lysozyme, and phospholipase A2.'), ('What is found in the submucosa of the duodenum and ileum?','Brunner glands in the duodenum secrete alkaline bicarbonate. Peyer patches in the ileum are macroscopic lymphoid aggregates and may hypertrophy in typhoid.')]), ('Fat Absorption: Luminal Phase',[ ('How are dietary triglycerides prepared for absorption?','Pancreatic lipase performs lipolysis, producing fatty acids and monoglyceride-related products. Bile acids then help form micelles.'), ('What is the role of micelles?','They solubilize lipid digestion products and deliver them to the enterocyte surface, where lipids enter mainly by passive diffusion.'), ('Which two major defects impair luminal fat absorption?','Chronic pancreatitis, by reducing pancreatic lipase activity, and bile-acid defects, by impairing micelle formation.')]), ('Bile Acids and Enterohepatic Circulation',[ ('What are the primary bile acids and their rate-limiting synthetic enzyme?','Cholic acid and chenodeoxycholic acid. Cholesterol 7alpha-hydroxylase is the rate-limiting enzyme in synthesis.'), ('How are bile salts formed?','Primary bile acids are conjugated with glycine or taurine to form bile salts.'), ('Where are bile acids reabsorbed and what happens in the colon?','They are reabsorbed mainly in the ileum and return to the liver via portal blood. Colonic bacteria deconjugate some bile acids, forming secondary bile acids such as deoxycholic and lithocholic acid.')]), ('Bile-Acid Defects: Causes of Fat Malabsorption',[ ('How can bile-acid synthesis be reduced?','Cirrhosis can impair bile-acid synthesis.'), ('What causes premature deconjugation of bile acids?','Small-intestinal bacterial overgrowth (SIBO).'), ('Which disorders impair bile-acid reabsorption or transport?','Ileal dysfunction from Crohn disease or tuberculosis impairs reabsorption. Primary biliary cholangitis and primary sclerosing cholangitis can impair bile transport through bile-duct damage.')]), ('Mucosal and Post-mucosal Fat Absorption',[ ('Which disorders cause mucosal-phase malabsorption?','Celiac disease, Whipple disease, and tropical sprue, due to loss of small-intestinal mucosal integrity.'), ('What happens to long-chain fatty acids after they enter enterocytes?','They are re-esterified with glycerol and assembled into chylomicrons.'), ('How are chylomicrons transported?','Via intestinal lymphatics before entering the bloodstream. Post-mucosal disorders include abetalipoproteinemia and intestinal lymphangiectasia.')]), ('Fatty Acids: Chain Length Matters',[ ('How are fatty acids classified by chain length?','Long chain: more than 12 carbons. Medium chain: 8-12 carbons. Short chain: fewer than 8 carbons.'), ('Which fatty acids require pancreatic lipolysis and micelles?','Long-chain fatty acids require both. Medium-chain fatty acids require neither; short-chain fatty acids also require neither.'), ('Where are short-chain fatty acids mainly produced and absorbed?','They arise from bacterial degradation of unabsorbed carbohydrate in the colon and are primarily absorbed there.')]), ('Carbohydrate Digestion',[ ('Where are disaccharidases located?','On the small-intestinal brush-border epithelium.'), ('What does lactase do?','It splits lactose into glucose and galactose.'), ('What does sucrase do?','It splits sucrose into glucose and fructose. Other brush-border disaccharidases include maltase and trehalase.')]), ('Carbohydrate Transport',[ ('How are glucose and galactose absorbed across the apical membrane?','By SGLT1, a sodium-glucose cotransporter that uses secondary active transport.'), ('How is fructose absorbed?','By facilitated diffusion through GLUT5.'), ('How do monosaccharides exit enterocytes?','Through basolateral GLUT2 into the capillary circulation. An SGLT1 defect causes familial glucose-galactose malabsorption syndrome.')]), ('Carbohydrate Malabsorption: Pattern Recognition',[ ('What is the difference between lactase deficiency and a mucosal defect?','Lactase deficiency causes selective carbohydrate malabsorption. A small-intestinal mucosal disorder causes global malabsorption.'), ('What are causes of lactase deficiency?','Congenital autosomal-recessive deficiency, acquired primary lactase non-persistence, or secondary reduction after intestinal infection or mucosal injury.'), ('Which diseases can produce global carbohydrate malabsorption?','Celiac disease, Whipple disease, and tropical sprue.')]), ('Lactose Intolerance: Mechanism and Presentation',[ ('What is the pathogenesis of lactose intolerance?','Undigested lactose reaches the colon, where bacteria ferment it to acids and gases including hydrogen, methane, and carbon dioxide.'), ('What symptoms occur after lactose ingestion?','Often within about 90 minutes: abdominal distension, bloating, cramps, and diarrhea. Children may have acidic stools, diaper dermatitis, poor growth, and irritability.'), ('How is lactose intolerance investigated?','Stool pH is acidic. In the lactose hydrogen breath test, excess breath hydrogen after lactose supports malabsorption; the lactose-glucose blood test is obsolete.')]), ('Lactose Intolerance: Management',[ ('What is the main management of lactose intolerance?','Dietary reduction or individualized restriction of lactose, while maintaining adequate nutrition.'), ('Why may calcium supplementation be needed?','Restricting dairy foods can lower calcium intake, so calcium adequacy should be assessed and supplemented when appropriate.'), ('What key distinction helps management?','Primary lactase non-persistence is common and chronic. Secondary deficiency may improve when the underlying intestinal disorder is treated.')]), ('Protein Digestion and Absorption',[ ('How is trypsin activated?','Enterokinase, also called enteropeptidase, from the enterocyte brush border activates trypsinogen to trypsin.'), ('What does trypsin activate?','Other pancreatic proteases including chymotrypsin and elastase. Carboxypeptidase and aminopeptidase act as exopeptidases.'), ('How are amino acids absorbed in the small intestine?','Predominantly through sodium-amino acid cotransport systems.')]), ('Protein Malabsorption',[ ('Which conditions cause global protein malabsorption?','Celiac disease, Whipple disease, and tropical sprue.'), ('What causes selective protein malabsorption?','Enterokinase deficiency, neutral amino-acid transport defects such as Hartnup disease, and dibasic amino-acid transport defects causing cystinuria.'), ('What does COLA stand for in cystinuria?','Cystine, ornithine, lysine, and arginine. These are excreted in excess in urine.')]), ('Abetalipoproteinemia: Core Concept',[ ('What is abetalipoproteinemia also called?','Neuroacanthocytosis.'), ('What is the molecular defect?','An autosomal-recessive defect in microsomal triglyceride transfer protein (MTP), impairing apoB48-related lipid assembly and chylomicron formation.'), ('What are the classic clinical features?','Hypolipidemia, steatorrhea, retinopathy or retinitis pigmentosa with night blindness, and neurologic ataxia due to vitamin E deficiency.')]), ('Abetalipoproteinemia: Diagnosis and Vitamin E',[ ('What is the characteristic peripheral smear finding?','Acanthocytes.'), ('What does postprandial small-bowel biopsy show?','Vacuolation of enterocytes, described in the notes as diagnostic.'), ('Why is vitamin E deficiency marked in this disease?','Fat malabsorption lowers vitamin E absorption, while reduced VLDL and chylomicron formation impair vitamin E transport from liver and intestine into blood.')]), ('Intestinal Lymphangiectasia: Mechanism',[ ('How do chylomicrons normally reach the blood?','They travel from the intestine through lymphatic channels before reaching systemic circulation.'), ('What is the mechanism of secondary intestinal lymphangiectasia?','Lymph-node obstruction raises lymphatic pressure, causing leakage or exudation into the intestinal lumen. Lymphoma and Crohn disease are examples.'), ('What is primary intestinal lymphangiectasia?','A condition with abnormally dilated lymphatic channels that leak into the intestinal lumen under pressure.')]), ('Intestinal Lymphangiectasia: Features and Management',[ ('What is the main clinical syndrome?','Protein-losing enteropathy with hypoalbuminemia, hypogammaglobulinemia, edema, ascites, and diarrhea.'), ('What important differentials cause low albumin?','Nephrotic syndrome causes urinary albumin loss, while liver disease causes reduced albumin production.'), ('How is it investigated and treated?','Fecal alpha-1 antitrypsin is elevated; CT may show small-bowel wall thickening and capsule endoscopy may help. Management includes a medium-chain triglyceride diet and treatment of the cause.')]), ('Rapid Review: High-yield Associations',[ ('SGLT1 defect','Familial glucose-galactose malabsorption.'), ('Neutral amino-acid transport defect','Hartnup disease with pellagra-like features: diarrhea, dermatitis, dementia.'), ('MTP defect','Abetalipoproteinemia: no effective chylomicron formation, acanthocytes, vitamin E-related ataxia.'), ('Dilated intestinal lymphatics','Intestinal lymphangiectasia with protein-losing enteropathy; use an MCT-based diet.')]), ] def add_text(slide, text, x,y,w,h, size=20, color=INK, bold=False, align=None): box=slide.shapes.add_textbox(Inches(x), Inches(y), Inches(w), Inches(h)); tf=box.text_frame; tf.clear(); tf.word_wrap=True; tf.margin_left=Inches(.03); tf.margin_right=Inches(.03); tf.margin_top=Inches(.02); tf.margin_bottom=Inches(.02); tf.vertical_anchor=MSO_ANCHOR.MIDDLE p=tf.paragraphs[0]; p.text=text; p.font.size=Pt(size); p.font.name='Aptos'; p.font.bold=bold; p.font.color.rgb=color if align: p.alignment=align return box def bg(slide, n, title): b=slide.background.fill; b.solid(); b.fore_color.rgb=WHITE shape=slide.shapes.add_shape(MSO_SHAPE.RECTANGLE,0,0,prs.slide_width,Inches(.32)); shape.fill.solid(); shape.fill.fore_color.rgb=NAVY; shape.line.fill.background() add_text(slide,'GIT ABSORPTION | QUESTION BANK',.55,.47,6.8,.3,10,BLUE,True) add_text(slide,title,.55,.82,12,.55,27,NAVY,True) ln=slide.shapes.add_shape(MSO_SHAPE.RECTANGLE,Inches(.55),Inches(1.49),Inches(1.25),Inches(.06)); ln.fill.solid(); ln.fill.fore_color.rgb=GOLD; ln.line.fill.background() add_text(slide,f'{n:02d}',12.1,.55,.6,.35,11,MUTED,True,PP_ALIGN.RIGHT) def qa_slide(n,title,qa): s=prs.slides.add_slide(blank); bg(s,n,title) card_y=1.72; gap=.18; total_h=5.25; h=(total_h-gap*(len(qa)-1))/len(qa) for i,(q,a) in enumerate(qa): y=card_y+i*(h+gap) c=s.shapes.add_shape(MSO_SHAPE.ROUNDED_RECTANGLE,Inches(.55),Inches(y),Inches(12.2),Inches(h)); c.fill.solid(); c.fill.fore_color.rgb=LIGHT if i%2==0 else PALE; c.line.color.rgb=RGBColor(215,226,231) qbox=s.shapes.add_shape(MSO_SHAPE.ROUNDED_RECTANGLE,Inches(.76),Inches(y+.18),Inches(1.18),Inches(.43)); qbox.fill.solid(); qbox.fill.fore_color.rgb=TEAL; qbox.line.fill.background(); add_text(s,'QUESTION',.83,y+.21,1.05,.22,8,WHITE,True,PP_ALIGN.CENTER) add_text(s,q,2.08,y+.12,10.3,.55,15,NAVY,True) add_text(s,a,.82,y+.72,11.7,h-.82,13.2,INK,False) add_text(s,'Prepared from the uploaded study pages. Educational revision resource.',.55,7.16,9,.18,8,MUTED) # Title s=prs.slides.add_slide(blank); s.background.fill.solid(); s.background.fill.fore_color.rgb=NAVY for x,y,w,h,c in [(0,0,13.333,.32,TEAL),(8.7,.7,4.5,5.9,RGBColor(21,73,108)),(9.3,1.35,3.25,.12,GOLD),(9.3,1.85,2.4,2.4,TEAL),(10.0,2.55,2.4,2.4,BLUE)]: sh=s.shapes.add_shape(MSO_SHAPE.RECTANGLE,Inches(x),Inches(y),Inches(w),Inches(h)); sh.fill.solid(); sh.fill.fore_color.rgb=c; sh.line.fill.background() add_text(s,'GIT Absorption\nand Selective\nMalabsorption',.7,1.35,7.4,2.1,35,WHITE,True) add_text(s,'Topic-sequenced question-and-answer revision deck',.74,3.82,6.6,.45,18,RGBColor(205,229,238)) add_text(s,'Fat • Carbohydrate • Protein • Selective malabsorption',.75,4.52,6.9,.3,13,WHITE,False) add_text(s,'Based on 8 uploaded gastroenterology study pages',.75,6.58,5.4,.25,10,RGBColor(190,212,221)) # navigation s=prs.slides.add_slide(blank); bg(s,0,'Topic Sequence') topics=['1. Foundations and small-intestinal histology','2. Fat absorption and bile acids','3. Carbohydrate digestion, transport, and lactose intolerance','4. Protein digestion and selective defects','5. Abetalipoproteinemia','6. Intestinal lymphangiectasia','7. Rapid review associations'] for i,t in enumerate(topics): y=1.75+i*.67; c=s.shapes.add_shape(MSO_SHAPE.ROUNDED_RECTANGLE,Inches(.7),Inches(y),Inches(11.8),Inches(.47)); c.fill.solid(); c.fill.fore_color.rgb=PALE if i%2==0 else LIGHT; c.line.fill.background(); add_text(s,t,.96,y+.08,11,.25,16,NAVY, i in [0,1,2,3,4,5,6]) for i,(title,qa) in enumerate(slides,1): qa_slide(i,title,qa) # closing s=prs.slides.add_slide(blank); s.background.fill.solid(); s.background.fill.fore_color.rgb=NAVY add_text(s,'End of Q&A Deck',.7,1.45,7.5,.65,33,WHITE,True) add_text(s,'Use the questions for active recall, then revisit the source pages for diagrams and tables.',.75,2.4,7.7,.55,18,RGBColor(202,225,234)) add_text(s,'High-yield approach: explain each answer aloud before revealing your notes.',.75,3.25,7.6,.4,16,WHITE) add_text(s,'GIT Absorption and Selective Malabsorption',.75,6.6,6,.25,11,RGBColor(190,212,221)) prs.save(OUT) print(OUT) ''') PY python "/tmp/workspace/git_absorption_qa/src/create_deck.py" python - <<'PY' from pptx import Presentation p='/tmp/workspace/git_absorption_qa/output/GIT_Absorption_and_Selective_Malabsorption_QA.pptx' prs=Presentation(p) print('slides',len(prs.slides),'size',__import__('os').path.getsize(p)) for i,s in enumerate(prs.slides[:3],1): print(i, [sh.text[:60] for sh in s.shapes if getattr(sh,'has_text_frame',False) and sh.text.strip()][:3]) PY

python - <<'PY' from pptx import Presentation from pathlib import Path p=Path('/tmp/workspace/git_absorption_qa/output/GIT_Absorption_and_Selective_Malabsorption_QA.pptx') prs=Presentation(str(p)) slides=list(prs.slides) print('slides:',len(slides),'bytes:',p.stat().st_size) for i,s in enumerate(slides,1): texts=[sh.text.replace('\n',' | ') for sh in s.shapes if getattr(sh,'has_text_frame',False) and sh.text.strip()] print(i, texts[0][:100] if texts else 'NO TEXT') assert len(slides)==22 assert all(any(getattr(sh,'has_text_frame',False) and sh.text.strip() for sh in s.shapes) for s in slides) print('VALID') PY

~/git_absorption_qa/output

intestinal absorption physiology fat carbohydrate protein absorption overview