The liver is divided into two sections: a right lobe and a left lobe. Both lobes are made up of cells called hepatocytes. These cells produce bile and secrete it into the bile ducts, which carry bile to the gallbladder where it is stored until used by the small intestine. The gallbladder is a pear-shaped sac under the right lobe of the liver. Between meals, it stores and concentrates bile, which is produced at a constant rate by the liver. After meals, the gallbladder releases bile into the duodenum to aid with digestion. The cystic duct carries bile from the gallbladder to the common bile duct, which empties into the duodenum. Entry of bile into the duodenum is regulated by layers of muscle called the sphincter of Oddi. The pancreas is a long, thin gland that lies horizontally behind the bottom part of your stomach. It makes digestive enzymes that flow through the pancreatic duct to the small intestine. These enzymes, along with bile from the gallbladder, break down food for use as energy by the body. The pancreas also makes insulin and glucagon, hormones that help regulate blood glucose (sugar) levels.