Terminal bronchiole

Terminal bronchiole

The Terminal bronchiole is the last part of the non-respiratory conducting region of the airway in the respiratory system. It branches off the respiratory bronchiole which leads to the alveolar duct and then to the microscopic alveolus where gas exchange takes place.

Structure

The terminal bronchiole is the most distal segment of the conducting zone. It branches into respiratory bronchioles which in turn divide into alveolar ducts. Each of these ducts opens into 5 or 6 alveoli. The terminal bronchioles and respiratory bronchioles are lined with simple cuboidal epithelium.

Function

The terminal bronchioles control airflow in the lungs. They also clean and humidify the incoming air. The epithelial cells lining the bronchioles secrete a thin layer of mucus that traps dust and other particles that could damage the lungs. The cilia on these cells beat in a coordinated fashion to move the mucus upwards, where it can be coughed up or swallowed.

Clinical significance

Diseases of the terminal bronchioles include bronchiolitis, asthma, and chronic obstructive pulmonary disease (COPD). These conditions can cause inflammation and constriction of the airways, leading to difficulty breathing.

See also

• Bronchiole
• Respiratory bronchiole
• Alveolar duct
• Alveolus

References

Terminal bronchiole Resources
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