Through which duct does bile flow from the liver to the duodenum, and what is bile's function?

• A. The hepatic duct; bile digests proteins.
• B. The cystic duct; bile neutralizes acids.
• C. The pancreatic duct; bile emulsifies fats.
• D. The common bile duct; bile emulsifies fats to aid digestion.

Answer: (D)

Bile travels from the liver to the duodenum primarily through the common bile duct, which carries bile into the duodenum, often joining with the pancreatic duct at the hepatopancreatic ampulla before release. Bile’s main digestive role is to emulsify fats—bile salts break large fat droplets into smaller ones, increasing surface area so pancreatic lipase can efficiently digest fats. The other ducts mentioned play different roles: the hepatic duct is an early part of the drainage from the liver, the cystic duct is the path to and from the gallbladder for storage, and the pancreatic duct carries pancreatic enzymes, not bile.