GIT 1 Flashcards
Pancreatic secretions
Isotonic fluid; low flow → high Cl−, high flow → high HCO3−.
Pancreatic proteases
trypsin, chymotrypsin, elastase, carboxypeptidases
Trypsinogen Converted to active enzyme by
deficiency:
enterokinase/ enteropeptidase,
both fat and protein malabsorption
Peyer patches location
Unencapsulated lymphoid tissue, found in lamina propria and submucosa of ileum
_______ catalyzes rate-limiting step of bile acid synthesis.
Cholesterol 7α-hydroxylase
Best initial test for cholestasis is
USG
Conjugated bilirubin undergoes 2 reactions in gut carried out by bacteria:
- Conjugated → Unconjugated by beta-glucuronidase
2. Unconjugated → Urobilinogen
Bile duct obstruction: Urine findings
Bilirubin in urine (dark urine)
Absent urobilinogen → Absent urobilin
Breast milk jaundice causes _____ hyperbilirubinemia that peaks at age of _____
indirect, 2 weeks
Breast milk jaundice mechanism:
Beta-glucuronidase in breast milk decojugates bilirubin → ↑absorption → ↑enterohepatic circulation of bilirubin
Urine and stool appearance unchanged
Dubin johnson syndrome: defect in _______
Why NO PRURITIS?
Multidrug resistance proteins
pruritis is caused by BILE SALTS. in obstructed diseases bile salt is not excreted and accumulates in skin causing PRURITIS
Biliary atresia: Fibro-obliterative destruction of _________
presentation:
extrahepatic bile ducts
newborn with persistent jaundice after 2 weeks of life, darkening urine, acholic stools, hepatomegaly.
Physiologic neonatal jaundice
At birth, immature UDP-glucuronosyltransferase , short HL of RBCs, ↑enterohepatic circulation of bilirubin (due to low bacteria in GIT) ► unconjugated hyperbilirubinemia
Physiologic neonatal jaundice Occurs ____ first 24 hours of life and usually resolves without treatment in ____
after
1–2 weeks
Crigler Najjar syndrome Type II is less severe and responds to ____ which _____
phenobarbital,
↑ liver enzyme synthesis.
Effect of cirrhosis on heart:
high output heart failure due to chronic splanchnic vasodilation and development of shunts
Sinusoidal HTN:
loss of protein rich fluid in space of Disse → ↑formation of hepatic lymph → Ascites
Parthenogenesis of autoimmune hepatitis
molecular mimicry
AST > ALT in nonalcoholic liver disease suggests _____
progression to advanced fibrosis or cirrhosis
Fulminant hepatitis:
Hepatic encapth within 6 weeks of hepatiic insult
Underlying mechanism of fulminant hepatitis is ___
hypersensitivity reaction to drug → immune mediated attack against hepatocytes.
Autopsy findings of fulminant hepatitis:
atrophy and shrunken
Alcoholic hepatitis histology
Swollen and necrotic hepatocytes with neutrophilic infiltration. Mallory bodies (intracytoplasmic eosinophilic inclusions of damaged keratin filaments).
Fibrous tissue (thickened collagenous bands) is stained with
stained blue with Masson trichrome stain
Hepatic encephalopathy → ↓NH3 removal causes
(due to renal failure, diuretics, bypassed hepatic blood flow post-TIPS).
the liver is the site of production of all major coagulation factors, except _______
factor VIII.
symptoms of volvulus:
bilious vomiting, abdominal distention, and bloody stools.
In children, volvulus almost always occurs in the _____
small intestine
in liver Acetaminophen is known to cause _____
centrilobular necrosis
drugs associated with granuloma formation include _____
SHAQ
sulfonamides, hydralazine, allopurinol, quinidine,, and methyldopa
______ can chelate and ↓effectiveness of other drugs (eg, tetracycline)
Calcium carbonate (antacid)
Hypolglycemia in hepatocellular carcinoma due to:
- ↑ metabolic rate of tumor
2. produces insulin like growth factor-II
Most common benign liver tumor_____
cavernous hemangioma
