Bronquio

Bronquio is one of the main air passages that conduct air from the trachea to the lungs. In humans there are two main bronchi: the right main bronchus and the left main bronchus. They enter the lungs at the hilum and diverge to supply each lung. The right main bronchus is typically wider, shorter, and more vertical than the left, which influences the pattern of inhaled object aspiration.

Each main bronchus gives rise to lobar (secondary) bronchi: three on the right for the three lung lobes and two on the left for the two lobes. These branch further into segmental (tertiary) bronchi, which subdivide throughout the bronchial tree. The walls of the larger bronchi contain cartilage in the form of rings or plates, a layer of smooth muscle, and a mucosa lined by pseudostratified ciliated epithelium with goblet cells. The submucosa houses seromucous glands.

Function and physiology: bronchi serve to conduct air to the smaller airways, humidify and filter it, and support mucociliary clearance and immune defenses of the lower respiratory tract.

Clinical relevance: inflammation of the bronchi is bronchitis; chronic bronchitis is a form of chronic obstructive pulmonary disease. Bronchial hyperreactivity and obstruction are features of asthma. Obstruction, infection, or tumors can involve a bronchus, and diagnostic procedures such as bronchoscopy or imaging help evaluate the bronchi.

Development: bronchi arise from the foregut endoderm as part of the developing tracheobronchial tree during embryogenesis.