What is the largest lymph trunk in the body?

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

Answer: (C)

The major lymphatic drainage pathway is the thoracic duct, which is the largest lymphatic trunk in the body. It collects lymph from most of the body—essentially everything below the diaphragm and the left side of the body above the diaphragm—and channels it into the venous system at the junction of the left internal jugular and left subclavian veins. This vast area of drainage makes the thoracic duct much larger than the other trunks. The jugular trunk drains the head and neck, the subclavian trunk drains the upper limb, and the parasternal trunks drain the medial aspects of the thorax and adjacent areas, so they are smaller and cover more limited regions.