Which statement correctly describes the two main lymphatic ducts and the areas they drain?

• A. The right lymphatic duct drains the legs.
• B. The thoracic duct drains the remainder of the body.
• C. The right lymphatic duct drains the left side of the body.
• D. The right lymphatic duct drains the right upper quadrant; the thoracic duct drains the remainder of the body.

Answer: (D)

The lymphatic system returns interstitial fluid to the venous system via two main channels: the right lymphatic duct and the thoracic duct. The right lymphatic duct collects lymph from the right side of the head and neck, the right upper limb, and the right side of the thorax, inserting into the right subclavian vein. The thoracic duct collects lymph from the remainder of the body—left side of the head and neck, left upper limb, left thorax, the abdomen, and both legs—into the left subclavian vein. This describes why the statement that the right lymphatic duct drains the right upper quadrant and the thoracic duct drains the remainder of the body is correct: it assigns each duct to the proper drainage regions. The other options either misstate which regions feed the right duct or omit the full scope of each duct’s drainage.