Which human organ stores and concentrates bile?

The gallbladder is the human organ that stores and concentrates bile.

Bile is produced continuously by the liver, then carried through bile ducts to the gallbladder for storage. When fatty food enters the small intestine, the hormone cholecystokinin signals the gallbladder to contract and release bile through the common bile duct.

Bile does not chemically digest fat in the same way that enzymes do. Instead, its bile salts emulsify fat into smaller droplets, increasing the surface area available to digestive enzymes. Bile also helps the body eliminate some waste products, including bilirubin.

The gallbladder is useful but not essential. After surgical removal, bile flows directly from the liver into the small intestine. A common mix-up is naming the liver as the storage organ: the liver makes bile, while the gallbladder stores and concentrates it.