left main bronchusmedical dictionary

It arises at the bifurcation of the trachea, passes in front of the oesophagus and enters the hilum of the left lung where it divides into a superior lobe bronchus and an inferior lobe bronchus. It is longer, of narrower calibre, and more nearly-horizontal than the right main bronchus, hence, aspirated objects enter it less frequently.

Synonyms: bronchus principalis sinister.

(05 Mar 2000)