Liver/Pancreas Patho

What is the functional unit of the liver?

hepatic lobule

What structures make up the portal triad?

portal vein, hepatic artery, bile duct

What vessel lies at the center of a hepatic lobule?

central vein

Five major functions of the liver

Metabolism, cholesterol regulation, detoxification, endocrine functions, storage of vitamins and iron

Approximately what fraction of liver tissue is needed to maintain function?

10%

What hematologic abnormalities are common in liver failure?

Anemia, thrombocytopenia, and coagulation defects

Why does liver failure cause endocrine abnormalities?

Cannot adequately metabolize sex hormones and aldosterone

What skin findings are characteristic of liver disease?

Jaundice, spider angiomas, and palmar erythema

What causes hepatic encephalopathy?

Accumulation of ammonia and other neurotoxins

What is hepatopulmonary syndrome?

Hypoxemia due to pulmonary vasodilation in chronic liver disease

Define jaundice

Abnormal accumulation of bilirubin in the blood causing yellowing

What are the four major mechanisms of jaundice?

Excess hemolysis, impaired bilirubin uptake, decreased conjugation, and bile flow obstruction

What is a common cause of prehepatic jaundice?

Hemolytic anemia

Name causes of intrahepatic jaundice.

Hepatitis, cirrhosis, and liver cancer

What commonly causes posthepatic jaundice?

Gallstones, bile duct strictures, and tumors

Which form of bilirubin is excreted in urine?

Conjugated bilirubin

What is kernicterus?

Irreversible bilirubin deposition in the brain of infants

What are the major consequences of portal hypertension?

Splenomegaly, ascites, and portosystemic shunts

What factors contribute to ascites in cirrhosis?

Portal hypertension, hypoalbuminemia, and sodium/water retention

What is cirrhosis?

Irreversible fibrosis with disruption of liver architecture and function

Which cells are the primary source of fibrosis in cirrhosis?

Activated hepatic stellate cells

What AST:ALT ratio suggests alcoholic liver disease?

Greater than 2:1

What are the leading causes of cirrhosis?

Alcohol, viral hepatitis, and nonalcoholic steatohepatitis

Which laboratory tests assess hepatocyte injury?

AST, ALT, and LDH

Which tests assess hepatic synthetic function?

Serum albumin, PT, and PTT

What is the normal function of the gallbladder?

Storage and concentration of bile

What are the three main factors promoting gallstone formation?

Abnormal bile composition, bile stasis, and gallbladder inflammation

What is cholecystitis?

Inflammation of the gallbladder, usually due to obstruction by a gallstone

What percentage of the pancreas is exocrine tissue?

More than 80%

What are the two most common causes of acute pancreatitis?

Gallstones and alcohol

What laboratory findings support acute pancreatitis?

Elevated serum amylase and lipase

How does alcohol contribute to chronic pancreatitis?

By promoting protein plugs, duct obstruction, and autodigestion

What long-term complications occur in chronic pancreatitis?

Diabetes mellitus and malabsorption