regional part of tributary of 86001 contributes to 'Regional_part_of' relation which holds between subtrees of a tree organ that is either of venous or lymphatic type. Pleural tributary of posterior intercostal vein Costal tributary of posterior intercostal vein Tributary of inferior epigastric vein Trunk of lymphatic tree organ Venous anastomosis Dorsal tributary of posterior intercostal vein Intervertebral tributary of posterior intercostal vein Collateral tributary of posterior intercostal vein Lateral cutaneous tributary of posterior intercostal vein Trunk of superior pulmonary vein Trunk of inferior pulmonary vein External-internal jugular communicating vein Tributary of deep palmar venous arch Trunk of lymphatic tree organ part Postnatal anatomical structure Communicating vein Segment of lymphatic tree organ