The thoracic (left lymphatic) duct begins as a dilation called the intestinal plexus hemiazygos trunk cisterna chyli thoracic ampulla

Before entering venous blood the lymph pass through the thoracic duct and the right lymphatic duct.
The thoracic (left lymphatic) duct begins as a dilation called the cisterna chyli.
Into this cisterna chyli the lymph  from the intestinal trunk and two lumbar lymphatic trunks flows. It is located at the lower end of the thoracic duct in most mammals.