Vein azygos, Lesser Superior

Vein azygos minor superior (lat. v. azygos minor superior) is an azygos vein belonging to the system of the superior vena cava.

This vein originates from the venous network located around the esophageal opening of the diaphragm. It then ascends along the right side of the chest between the right intercostal vessels and flows into the azygos vein at the level of the 4th thoracic vertebra.

The superior minor azygos vein collects blood from the upper part of the dorsal muscles, intercostal muscles and adjacent tissues. Its function is to drain venous blood into the azygos vein from the upper part of the chest.