The correct answer is "thoracic duct".
The thoracic duct (also called as the left lymphatic duct or the alimentary duct) is the structure wherein most of the lymph in the drained from the lymphatic vessels goes to this structure. In the thoracic duct, lymph flows up to the level of the brachiocephalic vein where lymph returns to the venous circulation.
The symbiotic relationship would be commensalism. It’s when one organism benefits and the other organism neither benefits nor is harmed.
Which signal are you talking about?
