What is a "duct"?

A duct is a tubular structure that transports various substances within the body. Ducts can be found in different organs and systems, such as the respiratory system, digestive system, and excretory system. They serve as pathways for the movement of fluids, gases, and secretions, including saliva, tears, sweat, bile, and digestive enzymes. Ducts can vary in size and complexity, ranging from small, intricate ducts within glands to larger ducts that connect organs. These structures play a vital role in maintaining the proper functioning and regulation of bodily processes, ensuring the transport and distribution of necessary substances for physiological functions.