Quick Facts
Origin: Union of small tributaries.
Course: Along superior surface of respiratory diaphragm.
Tributaries: None.
Drainage: Superior surface of diaphragm.
Origin
The superior phrenic veins are formed by the union of small venules on the superior surface of the respiratory diaphragm.
Course
The superior phrenic veins course along the superior surface of the respiratory diaphragm and are accompanied by the superior phrenic arteries. They descend posteriorly to unite with the hemiazygos and azygos veins.
Tributaries
There are no named tributaries; however, they do form an anastomosis with the musculophrenic and pericardiacophrenic veins to ensure constant drainage of the diaphragm.
Structures Drained
The superior phrenic veins drain the vertebral portion of the respiratory diaphragm.