Thoracic duct: largest lymphatic trunk in the body, draining lymph into the venous system from the whole body except the right upper quadrant.
Carries chyle, a milky white fluid from fat digestion in the intestine.
The duct appears beaded due to numerous valves in its lumen.
Extent, Measurements and Area of Drainage
Drains the whole body except the right upper quadrant, which is drained instead by the right lymphatic duct.
Right upper quadrant: right side of the head and neck, right side of the chest wall, right lung, right side of the heart, right surface of the liver, and right upper limb.
Extent: lower border of the T12 vertebra (continuation of the cisterna chyli) to the junction of the left internal jugular and left subclavian veins.
Measurements: length 45 cm; width of lumen 5 mm at the ends, narrower in the middle.