It arises above the level of the right pulmonary artery, and for this reason is named the eparterial bronchus.

[1] All other distributions falling below the pulmonary artery are termed hyparterial.

The classification of eparterial and hyparterial is attributed to Swiss anatomist and anthropologist Christoph Theodor Aeby, and is central to his model of the anatomical lung.

He presented this model in a monograph titled, "Der Bronchialbaum der Säugethiere und des Menschen, nebst Bemerkungen über den Bronchialbaum der Vögel und Reptilien".

[2] This article incorporates text in the public domain from page 1097 of the 20th edition of Gray's Anatomy (1918)