The cystic duct is a small tube that connects the gallbladder to the bile duct. It plays a crucial role in the digestive system by allowing bile, a fluid produced by the liver, to flow in and out of the gallbladder. Bile helps in the digestion of fats. When food enters the small intestine, the gallbladder releases bile through the cystic duct into the bile duct, which then transports it to the intestine. The cystic duct can also store bile when the gallbladder is not actively releasing it, ensuring that bile is available when needed for digestion.