26.5 : 气管

The trachea or windpipe begins at the larynx and extends into the mediastinum, bifurcating into two main bronchi in the mid-thorax region.

The tracheal wall consists of four layers: the mucosa, submucosa, hyaline cartilage, and adventitia.

The mucosa is equipped with ciliated pseudostratified columnar epithelium and lamina propria, offering protection against airborne dust particles.

The submucosa contains areolar connective tissue with seromucous glands, and the hyaline cartilage features 16 to 20 incomplete rings that provide semi-rigid support, preventing airway obstruction and accommodating esophageal expansion during food passage.

The adventitia is composed of areolar connective tissue that attaches the trachea to adjacent tissues.

The flexibility of the trachea, provided by its elastic elements, is vital for its movement during our breathing cycle.

The carina, an extended portion of the final tracheal cartilage, is crucial in initiating cough reflexes to expel foreign objects.

Tracheal obstruction can be life-threatening, and methods like the Heimlich maneuver, a tracheotomy, or intubation are performed to remove such blocks.