What is thoracic duct?

Option B

 The lymphatics and associated lymph nodes form a network draining the viscera and the more superficial body structures before returning to the blood by way of the thoracic duct. The thoracic duct is the larger of the two and responsible for lymph drainage from the entire body except for the right sides of the head and neck, the right side of the thorax, and the right upper extremity which are primarily drained by the right lymphatic duct.