luftrören

Luftrøren, commonly known as the trachea, is the main airway that transports air from the larynx to the lungs. It is part of the lower respiratory tract and lies in front of the esophagus in the neck and upper chest. In adults, the trachea is about 10 to 12 centimeters long and roughly 2 centimeters in inner diameter, with variation based on body size.

Anatomy: The trachea is supported anteriorly and laterally by C-shaped hyaline cartilage rings that prevent collapse. These rings are connected by elastic tissue and fibrous strands, while the posterior wall is membranous and contains smooth muscle (the trachealis). The lumen is lined by pseudostratified ciliated columnar epithelium with goblet cells, which facilitate mucociliary clearance by moving mucus and trapped particles upward toward the larynx. The trachea starts below the cricoid cartilage and ends at the carina, where it divides into the left and right main bronchi.

Function: It provides a clear airway for airflow and conditions inspired air by warming, humidifying, and filtering it. The mucociliary escalator plays a key role in removing dust, pathogens, and debris from the respiratory tract.

Supply and innervation: Blood supply comes from bronchial arteries and branches of the inferior thyroid arteries, with venous drainage to the azygos system and other thoracic veins. Autonomic nerves from the vagus nerve regulate mucus production and bronchial tone.

Development: The trachea develops from the foregut endoderm, with surrounding mesenchyme forming cartilage rings and supporting tissues; the lining epithelium differentiates into respiratory-type cells.

Clinical relevance: The trachea can be affected by infections (tracheitis), structural weakness (tracheomalacia), stenosis, or tumors. Airway management procedures include endotracheal intubation and tracheostomy.