Length of thoracic duct is:: (A) 20 cm, (B) 25 cm, (C) 30 cm, (D) 45 cm
Answer is D. In adults the thoracic duct, including the confluence of lymph trunks (or the cisterna chyli in the small propoion in whom the latter is saccular) is 38-45 cm in length and extends from the second lumbar veebra to the base of the neck.