Right inferior lobar bronchus

At a glance

English

Right inferior lobar bronchus

Latin (TA2)

Bronchus lobaris inferior dexter

System

Respiratory

Region

Thorax

Side

Single, on the midline

About the right inferior lobar bronchus

The right inferior lobar bronchus is the continuation of the intermediate bronchus after the middle lobar bronchus has left its front wall. It runs downwards and backwards into the lower lobe, the large part of the right lung behind and below the oblique fissure. The lobe rises high at the back, its top lying about level with the fourth rib behind, and its base rests on the dome of the diaphragm.

Almost at once it gives off from its posterior wall the superior segmental bronchus, which turns sharply backwards to the upper part of the lobe. The trunk then becomes a short basal stem that gives the medial basal segmental bronchus and finally splits into the anterior, lateral and posterior basal segmental bronchi. On the right all four basal branches are normally separate, so the lobe has five segmental airways in all.

Its wall has cartilage plates, smooth muscle and a ciliated, mucus-secreting lining, and it carries air only. The right pulmonary artery spirals round its lateral and posterior side as both descend, and the inferior pulmonary vein lies below and in front.

The right lower lobe bronchus lies in the most direct line from the trachea, so inhaled foreign bodies, food and secretions are more likely to reach it than any other lobar airway. In an upright person the basal segments receive aspirated material, and in someone lying on the back the superior segment does. Collapse of the lobe shows on a frontal X-ray as a triangular shadow next to the spine with loss of the outline of the right half of the diaphragm.

Function and supply

Begins at

The intermediate bronchus within the hilum, below the origin of the middle lobar bronchus.

Ends at

Divides into the superior segmental bronchus and the medial, anterior, lateral and posterior basal segmental bronchi.

Function

Conducts air to and from the lower lobe of the right lung.

Nerve supply

Pulmonary plexus (vagal and sympathetic fibres).

Blood supply

Right bronchial artery.