Normal copper homeostasis is maintained primarily by which process?

Normal copper homeostasis is maintained primarily by which process?

• A. Urinary excretion
• B. Biliary excretion
• C. Intestinal absorption
• D. Renal filtration

Answer: (B)

Copper balance is controlled mainly by hepatic biliary excretion. After absorption, copper is transported to the liver, where excess is excreted into bile via ATP7B-mediated pathways, making biliary elimination the primary means of maintaining normal copper levels. Urinary excretion occurs but to a much smaller extent, and renal filtration is not a major route because most copper is bound to proteins and not freely filtered. Intestinal absorption sets how much copper enters the body, but the ongoing balance is governed by the liver’s ability to excrete copper into bile.

Copper balance is controlled mainly by hepatic biliary excretion. After absorption, copper is transported to the liver, where excess is excreted into bile via ATP7B-mediated pathways, making biliary elimination the primary means of maintaining normal copper levels. Urinary excretion occurs but to a much smaller extent, and renal filtration is not a major route because most copper is bound to proteins and not freely filtered. Intestinal absorption sets how much copper enters the body, but the ongoing balance is governed by the liver’s ability to excrete copper into bile.