High Quality Content by WIKIPEDIA articles! In human anatomy, the thoracic duct is an important part of the lymphatic system?it is the largest lymphatic vessel in the body. It is also known under various other names including the alimentary duct, chyliferous duct, the left lymphatic duct and Van Hoorne's canal.It collects most of the lymph in the body (except that from the right arm and the right side of the chest, neck and head, and lower left lobe of the lung, which is collected by the right lymphatic duct) and drains into the systemic (blood) circulation at the left brachiocephalic vein, right between where the left subclavian vein and left internal jugular connect.