right lymphatic duct, a vessel that conveys lymph from the right upper quadrant of the body into the bloodstream in the neck at the junction of the right internal jugular and the right subclavian veins. About 1.25 cm long, the duct courses over the medial border of the scalenus anterior. At its orifice are two semilunar valves that prevent venous blood from flowing backward into the duct. Lymph drains into the right lymphatic duct from numerous capillaries and vessels and from three lymphatic trunks in the right quadrant. Compare thoracic duct. See also lymphatic system.
