: bronchi, /ˈbrɒŋkaɪ/ BRONG-ky) is a passage or airway in the lower respiratory tract that conducts air into the lungs.

The carina of the trachea is located at the level of the sternal angle and the fifth thoracic vertebra (at rest).

About 2 cm from its commencement it gives off a branch to the superior lobe of the right lung, which is also called the eparterial bronchus.

The right bronchus now passes below the artery, and is known as the hyparterial branch which divides into the two lobar bronchi to the middle and lower lobes.

This cellular lining has cilia departing towards the mouth which removes dust and other small particles.

[6] The cartilage and mucous membrane of the main bronchus (primary bronchi) are similar to those in the trachea.

Mucus plays an important role in keeping the airways clear in the mucociliary clearance process.

As branching continues through the bronchial tree, the amount of hyaline cartilage in the walls decreases until it is absent in the bronchioles.

[9] It can have multiple variations and, although usually asymptomatic, it can be the root cause of pulmonary disease such as a recurrent infection.

Exchange of gases between the air in the lungs and the blood in the capillaries occurs across the walls of the alveolar ducts and alveoli.

The alveolar ducts and alveoli consist primarily of simple squamous epithelium, which permits rapid diffusion of oxygen and carbon dioxide.

Bronchial wall thickening, as can be seen on CT scan, generally (but not always) implies inflammation of the bronchi (bronchitis).

If food, liquids, or foreign bodies are aspirated, they will tend to lodge in the right main bronchus.

If a tracheal tube used for intubation is inserted too far, it will usually lodge in the right bronchus, allowing ventilation only of the right lung.

The inhaler administers a bronchodilator, which serves to soothe the constricted bronchi and to re-expand the airways.