Papillary ducts represent the most distal portion of the collecting duct. Medical imaging such as ultrasound is useful for detecting bile duct blockage. Is established between the pump and the pipe duct. Obstruction of the nasolacrimal duct may occur. Catheters can be inserted into a body cavity, duct, or vessel. It can result from such causes such as a rapidly expanding duct of pipe. The increased production of sebum can lead to a blockage of the sebaceous gland duct. It enters the oral cavity via the parotid duct. Preventive treatment of severe dryness with measures such as nasolacrimal duct blockage is important. Inflammation associated with blockage of the duct is sometimes termed "obstructive sialadenitis". There are also extra pressure losses in the bypass duct and an extra propelling nozzle. Several problems can arise within the common bile duct. Behind rests the inferior vena cava, and the common bile duct. Bile is collected and delivered through the common hepatic duct. He escaped a second time by crawling through a ventilation duct.