Which bile duct leads into and out of the gallbladder?

The cystic duct is the bile duct that leads into and out of the gallbladder. It connects the gallbladder to the common hepatic duct, which carries bile from the liver to the small intestine. The cystic duct is about 1-2 inches long and is lined with smooth muscle. When the gallbladder contracts, bile is forced into the cystic duct and then into the common hepatic duct.