The main and segmental bronchi

Abstract 

The trachea bifurcates at the level of T4 in the cadaver; in the living subject it descends to T6 in full inspiration. The right main bronchus is wider, shorter and more vertical than the left; therefore more likely to aspirate a foreign body or to be inadvertently entered by a catheter or endotracheal tube. The lungs are divided into bronchopulmonary segments, each with its own blood supply and bronchial branch. The right lung has an upper, middle and lower lobe, the left an upper and lower lobe, the upper having a lingular segment, somewhat equivalent to the right middle lobe but supplied from the upper lobe bronchus. The upper lobe on each side comprises an apical, anterior and posterior segment, the lower lobe an apical and posterior, lateral and anterior basal segment. The right lower lobe also has a small medial basal (cardiac) segment. The right middle lobe has a medial and lateral segment, while the lingula has a superior and inferior segment. The segmental anatomy of the lungs enables segmental resections to be performed and is important in postural drainage of the lungs.

Keywords: anatomy, bronchopulmonary, bronchus, lingula, lobe, lower, middle, postural drainage, right, segmental resection, segments, upper