Question

Which statement is true of the thoracic duct?

a. It forms from the merging of collecting vessels on the right side of the body.
b. It drains the lymph from the entire left side of the body and the right abdomen and leg.
c. It is the smallest lymphatic vessel in the body.
d. It originates from the right subclavian vein.

Answer 1

The thoracic duct drains lymph from the entire left side of the body as well as the right abdomen and leg, and begins at the cisterna chyli beneath the diaphragm.

Step-by-step explanation:

The correct answer to the question about the thoracic duct is: b. It drains the lymph from the entire left side of the body and the right abdomen and leg. The thoracic duct begins just beneath the diaphragm in the cisterna chyli, a sac-like chamber. It receives lymph from the lower abdomen, pelvis, and lower limbs by way of the left and right lumbar trunks and the intestinal trunk. Lymph from the upper right side of the body is instead drained by the right lymphatic duct. Therefore, the thoracic duct is responsible for draining a significant portion of the body's lymph, including the entire left side, the right abdomen, and leg.