Chapter 38: Disorders of Hepatobiliary & Pancreas Function

The functions and disorders of the liver, gallbladder, and exocrine pancreas are central to this chapter, beginning with the liver’s anatomy, including its dual blood supply via the hepatic artery and portal vein, and its lobules, which house critical Kupffer cells for filtration. Metabolically, the liver manages glucose homeostasis through glycogenesis and gluconeogenesis, synthesizes crucial proteins like albumin and clotting factors, processes lipids, and detoxifies ammonia into urea. Bile is secreted for fat digestion, and its impaired flow leads to cholestasis, which, along with excessive red blood cell destruction or liver damage, can cause jaundice due to bilirubin accumulation. Liver function tests utilize serum enzymes, such as ALT and AST, to assess hepatocellular injury. Major liver pathologies include hepatotoxic disorders involving multi-phase drug metabolism pathways (like the CYP P-450 system) and various forms of viral hepatitis (A, B, C, D, E), which differ significantly in transmission and potential for chronicity. Chronic liver damage, whether from alcohol abuse, Nonalcoholic Fatty Liver Disease (NAFLD), or other causes, progresses to cirrhosis, marked by fibrous tissue and nodules. This structural change results in portal hypertension, leading to complications like ascites, splenomegaly, and highly dangerous esophageal varices. Liver failure manifests widely, affecting hematologic and endocrine systems and causing hepatic encephalopathy. Disorders of the gallbladder often involve cholelithiasis, the formation of gallstones primarily composed of cholesterol, which can cause obstruction, leading to inflammation (cholecystitis). Lastly, the exocrine pancreas, which secretes inactive digestive enzymes, is susceptible to acute pancreatitis, a reversible inflammatory process often triggered by gallstones or alcohol, characterized by autodigestion, and chronic pancreatitis, which involves irreversible fibrotic destruction and eventually leads to deficiencies causing diabetes and fatty stools (steatorrhea). Pancreatic cancer, often adenocarcinoma, typically presents late and has a poor prognosis.