Disorders of Hepatobiliary and Exocrine Pancreas Function

Chapter 38: Disorders of Hepatobiliary and Exocrine Pancreas Function

Introduction

• Overview of liver, pancreas, and gallbladder functions and disorders.

Objectives

• Blood Supply of the Liver:

  • Unique attributes of the liver's blood supply facilitate portal hypertension.

• Functions of Liver, Pancreas, Gallbladder:

  • Describe the functional roles of liver and pancreatic secretions (both exocrine and endocrine).

• Causes of Jaundice:

  • Clarify what occurs in urine and stool when bilirubin conjugation fails due to liver dysfunction.

• Liver Function Tests:

  • Identify the laboratory tests that assess liver function.

• Hepatitis Causes:

  • List various causes of hepatitis, including viral types.

• Hypersensitivity in Hepatitis:

  • Identify hypersensitivity types correlated with liver injury in hepatitis.

• Alcohol-Induced Liver Disease:

  • Explain stages of alcohol-induced liver conditions, and describe alternative causes of fatty liver.

• Cirrhosis and Liver Failure:

  • Define cirrhosis, its progression to liver failure, and typical presentations of affected patients.

• Liver Cancer:

  • Distinguish between primary and metastatic liver cancer prevalence.

• Hepatobiliary System Components:

  • Name and describe all components of the hepatobiliary system and major biliary disorders.

• Pancreatic Secretions in Pathophysiology:

  • Relate pancreatic secretions to acute pancreatitis. Explain signs/symptoms of the condition.

• Pancreatic Cancer:

  • Enumerate causes of pancreatic cancer and typical prognoses.

Accessory Organs of the Gastrointestinal Tract

• Liver:

  • Has a dual blood supply from the hepatic portal vein and hepatic artery.

  • Hepatic Portal Vein:

  • Drains the digestive tract and major abdominal organs.

  • Hepatic Veins:

  • Valveless veins directing blood into the inferior vena cava.

  • Hepatic Artery:

  • Supplies oxygen-rich blood to the liver.

• Gallbladder:

  • Storage organ for bile.

• Exocrine Pancreas:

  • Secretes digestive enzymes.

Liver Structure

• Blood Flow:

  • Blood from the hepatic portal vein and hepatic artery mix in sinusoids, which then converge into central veins.

  • Central Veins:

  • Lead to the hepatic vein and ultimately the inferior vena cava.

• Hepatic Cells:

  • Located along the sinusoids, they modify the blood's composition and release bile into canaliculi.

Functions of the Liver

• Production and Secretion:

  • Bile salts production essential for digestion.

• Bilirubin Elimination:

  • Process of eliminating metabolic waste from red blood cells.

• Metabolism:

  • Involves carbs, fats, proteins, drugs, and steroid hormones.

  • Carbohydrate Metabolism:

    • Conversion of sugars to glycogen, glucose, and fats.

  • Protein Metabolism:

    • Amino acids synthesis into proteins; ammonia conversion into urea.

  • Lipid Metabolism:

    • Oxidize fats for energy; synthesize and package into lipoproteins.

• Storage and Filtration:

  • Minerals, vitamins, and blood filtration for pathogens.

Assessment of Liver Function

• Serum Aminotransferase Levels (AST, ALT):

  • Indicators of liver cell injury.

• Bilirubin, GGT, Alkaline Phosphatase:

  • Tests measure hepatic excretory function.

• Imaging Techniques:

  • Includes ultrasonography, CT scans, MRI for liver structure evaluation.

• Angiography:

  • Visualizes hepatic/portal circulation.

• Liver Biopsy:

  • Provides tissue specimens for microscopy.

Hepatitis Overview

• Types:

  • Includes Hepatitis A (HAV), B (HBV), B-associated delta (HDV), C (HCV), and E (HEV).

• Transmission Routes:

  • HAV: Fecal-oral.

  • HBV, HCV: Blood/serum, sexual contact, IV drug abuse.

  • HEV: Fecal-oral.

• Symptoms and Carrier States:

  • HAV: Abrupt onset, fever, malaise, no carrier state.

  • HBV: Similar symptoms, possible chronic phase, carrier state exists.

  • HCV: Often asymptomatic; can lead to chronic disease.

  • HEV: Similar to HAV; high mortality in pregnancy.

Alcoholic Liver Disease

• Stages:

  • Fatty liver (steatosis), alcoholic hepatitis, cirrhosis.

  • Fatty liver: Enlarged liver with fat deposits.

  • Hepatitis: Inflamed liver cells, potential liver failure.

  • Cirrhosis: Scar tissue obstructs blood flow (sinusoids).

Cirrhosis Manifestations

• Symptoms:

  • Weight loss, weakness, anorexia, abdominal discomfort, jaundice, jaundiced skin (pruritus), abdominal pain.

• Complications:

  • Portal hypertension leading to ascites, esophageal varices, and splenomegaly.

Portal Hypertension

• Consequences:

  • Increased pressure in veins causes varicosities and shunts; organs engorge.

  • Results in complications such as Caput Medusae, hemorrhoids, and hepatic encephalopathy.

Primary Liver Cancer

• Types:

  • Hepatocellular carcinoma: Associated with hepatitis and cirrhosis.

  • Cholangiocarcinoma: Affects bile duct cells, linked to chronic inflammation.

Disorders of the Gallbladder

• Cholelithiasis:

  • Gallstones formed from cholesterol, calcium salts, or mixed types.

• Cholecystitis:

  • Inflammation from irritants in concentrated bile.

• Choledocholithiasis:

  • Stones present in common bile duct.

• Cholangitis:

  • Inflammation of the common bile duct.

Pancreatic Disorders

• Exocrine vs. Endocrine Functions:

  • Exocrine pancreas produces digestive juices; endocrine pancreas releases insulin.

• Common Causes of Acute Pancreatitis:

  • Includes gallstones, alcohol abuse, hyperlipidemia, hyperparathyroidism, infections, and trauma.

• Chronic Pancreatitis:

  • Symptoms mirror acute pancreatitis; causes digestive and glucose control problems.

• Pancreatic Cancer:

  • High mortality; link to age, smoking, and dietary factors.

Conclusion

• Knowledge of hepatobiliary and pancreatic disorders is crucial for diagnosis and treatment in clinical practice.