ABSTRACT
The liver is an important target organ for toxicity. It is especially susceptible to toxic agents absorbed from the gastrointestinal tract as well as substances that must be metabolically activated to produce cellular injury. The liver excretes bile, which in many species flows from the liver to the gallbladder via the common hepatic duct and is conducted from the gallbladder to the duodenum via the common bile duct. In comparison with the liver, the exocrine pancreas makes an insignificant contribution to drug metabolism and detoxification and is seldom identified as a target organ of xenobiotic toxicity. The induction of hepatocellular enzymes, hypertrophy, hyperplasia, and hepatomegaly are generally considered to be reversible and adaptive in nature when noted in the absence of indicators of toxicity. Although part of a morphological continuum with focal hyperplasia, adenomas are larger and usually grossly apparent as nodular or multinodular, well-demarcated masses.
