Opposite Flows in a Single Vessel?
2021.03.09 note
In mice, the thoracoepigastric vein anastomoses with the inferior vena cava and the subclavian vein.
Blood in the subclavian vein flows to the right atrium, and blood in the inferior vena cava flows to the right atrium.
What!
In representative experimental mice (C57BL/6J, BALBc, SCID, MXH10/lpr), bidirectional blood flow in the thoracoepigastric vein always occurs in the central region between the subiliac lymph node and the proper axillary lymph node.
Due to an anastomosis, blood flow in the thoracoepigastric vein is routed to the subclavian vein and the inferior vena cava, respectively.
The amount of the blood flow from the new veins is equal to the total blood flow to the subclavian vein and the inferior vena cava, thereby upholding the law of mass conservation.
The same phenomenon is observed in dogs, cats, horses, cows, etc.
Right direction: subclavian vein via the proper axillary lymph node.
Left direction: inferior vena cava via the subiliac lymph node.