GI Flashcards
Primary Sclerosing Cholangitis (PSC)
Onion skin bile duct fibrosis
Beading of bile ducts
Middle-aged men, IBD (UC_
pANCA+
Primary Biliary Cholangitis (PBC)
AI rxn –> lymphocytic infiltrate –> granulomas
Middle aged women; insidious presentation e.g. with pruritis, fatigue; can have signs of cholestasis (jaundice, pale stool, dark pee) & hypercholesterolemia (e.g. xanthelasma)
Anti-mitochondrial Ig
Assoc w/ other AI conditions ( (Sjogrens, Hashimoto, CREST, RA, celiac)
Lymphatic drainage above pectinate (dentate) line
internal iliac and inferior mesenteric lymph nodes (common path of colorectal adenocarcinoma spread)
Lymphatic drainage below pectinate (dentate) line
Superficial inguinal LNs
Treatments for hepatic encephalopathy (and their mechs)
Lactulose: increase conversion of ammonia (NH3) into ammonium (NH4+) which can be excreted, and lowers colonic pH
Rifamixin, Neomycin: reduce NH3-producing gut bacteria, hence reducing NH3 levels
Causes of acute pancreatitis
"I GET SMASHED" Idiopathic Gallstones* Ethanol* Trauma Steroids Mumps Autoimmune disease Scorpion sting Hypercalcemia/HyperTAG (>1000) ERCP Drugs (sulfa, NRTIs, protease inhibitors)
Gallstones and alcohol make up 80% of all acute pancreatitis
Presentation of colon and rectal cancers:
- Right sided (ascending colon)
- Left sided (descending colon)
- Rectosigmoid involvement
- Rectal adenocarcinoma
- R colon: exophytic mass d/t larger caliber of ascending colon; BLEEDING + anemia sx, weight loss
- L colon: infiltrates bowel wall, encircles lumen –> constipation, abd distention, N/V, OBSTRXN sx
- Rectosigmoid: hematochezia
- Rectal adenocarci: tenesmus and small caliber stools
Heme conversion into bilirubin pathway
heme –heme oxygenase–> biliverdin (greenish color of bruises) –biliverdin reductase–> unconjugated bilirubin –UDPGT–> conjug bilirubin –gut bact–> urobilinogen. 80% urobilinogen –> stercobilin (makes poop brown). Of remaining 20%: 10% to kidney –> urobilin (makes pee yellow), 90% to liver (enterohepatic circulation)
3 types of groin hernias:
- Direct
- Indirect
- Femoral
- Direct: through Hesselbach triangle (rectus abdominal medially, inferior epigastrics laterally, inguinal ligament below). d/t weak transversalis fascia. Goes thru external ring and external fascia only
- Indirect: INto the internal and external inguinal rings, and INto the scrotum. Inferior epigastrics medially, inguinal ligament below. Follows path of descent of testes thru patent processus vaginalis; covered by all 3 layers of spermatic fascia.
- Femoral: more common in FEMales; protrudes below inguinal ligament, thru fem canal below and lateral to pubic tubercle
Examples of true and false diverticula
- True (involves all mucosal layers): normal appendix, Meckel diverticulum
- False (only some layers e.g. mucosa and submucosa): Zenker esoph diverticula, diverticulosis
Biliary atresia vs. Breast milk jaundice
- Biliary atresia: obstrxn of extrahepatic bile duct; biliary tree destroyed (immune or viral). p/w jaundice, dark urine, pale stools in first 2 mo. Biopsy: intrahepatic bile duct prolif, portal tract edema, fibrosis. CONJUGATED hyperbili.
- Breast milk jaundice: causes INDIRECT hyperbili that peaks at 2 wks. Beta-glucuronidase in breast milk deconjugates bili –> increased absorption and enterohepatic bili circulation. Normal urine and stool
Parietal vs. Chief cell histology
Parietal cells are pink, puffy cells. Like pink, puffy balloons they float up and in the upper region of gastric pits. Chief cells are in the lower region, have RER making them blue, and are smaller.
Zollinger-Ellison syndrome
Gastrinoma of duodenum or pancreas. Acid hypersecretion causes recurrent duod/jejunal ulcers; abdom pain (PUD, distal ulcers), diarrhea (malabsorption). Gastrin levels will remain high even after administering secretin. Can be assoc w/ MEN1. Gastrin hypersecretion causes gastric fold (rugae) enlargement
Risk factors for pancreatic cancer
- Smoking/tobacco
- Chronic pancreatitis (esp > 20 yrs)
- DM
- Age > 50 yo
- Jewish and AA males
Gardner syndrome
FAP + osteomas, fibromatosis
