Which trunk is described as the largest lymph trunk in the body?

• A. Jugular Trunk
• B. Subclavian Trunk
• C. Thoracic duct
• D. Parasternal Trunk

Answer: (C)

The largest lymph trunk is the thoracic duct. It gathers lymph from the majority of the body—lower limbs, pelvis, abdomen, and the left side of the thorax, head, and neck—and even from the intestinal lymphatics via the cisterna chyli. It begins near L2 as the cisterna chyli, travels up through the posterior mediastinum, and drains into the left venous angle (where the left internal jugular and left subclavian veins meet). Because it collects from such a wide region and carries a large volume of lymph, it is the largest trunk. In contrast, the jugular trunk drains the head and neck, the subclavian trunk drains the upper limb, and the parasternal trunk drains the medial thoracic wall, all of which cover smaller areas.