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 serves as the main drainage channel for lymph, collecting fluid from the cisterna chyli in the abdomen and from the lower body, plus the left side of the head, neck, thorax, and upper limb. On the right side of the body, lymph from the head, neck, and upper limb drains mostly into the right lymphatic duct, but that channel handles a far smaller territory than the thoracic duct. Because the thoracic duct gathers lymph from a vast area, it is the widest and most substantial lymphatic vessel, and it empties into the left venous angle at the junction of the left internal jugular and left subclavian veins. In contrast, the jugular trunk drains the head and neck, the subclavian trunk drains the upper limb, and the parasternal trunks drain the anterior chest wall; all are smaller.