Right main bronchus - Bronchus principalis dexter
The Right Bronchus (bronchus dexter), wider, shorter, and more vertical in direction than the left, is about 2.5 cm. long, and enters the right lung nearly opposite the fifth thoracic vertebra.
The azygos vein arches over it from behind; and the right pulmonary artery lies at first below and then in front of it. About 2 cm. from its commencement it gives off a branch to the upper lobe of the right lung. This is termed the eparterial branch of the bronchus, because it arises above the right pulmonary artery. The bronchus now passes below the artery, and is known as the hyparterial branch; it divides into two branches for the middle and lower lobes.
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).