- The trachea, commonly known as the windpipe, is a vital component of the respiratory system that serves as the primary airway connecting the larynx (voice box) to the bronchi of the lungs. It plays a critical role in conducting air in and out of the lungs, thus facilitating respiration.
- The trachea is a flexible, cylindrical tube approximately 10 to 12 centimeters long in adults and about 2 to 2.5 centimeters in diameter. It is located anterior to the esophagus and extends from the lower edge of the larynx at the level of the sixth cervical vertebra down to the fifth thoracic vertebra, where it bifurcates into the left and right main bronchi at a region known as the carina.
- Structurally, the trachea is reinforced by C-shaped cartilaginous rings—typically 16 to 20 in number—that maintain the airway’s open shape and prevent collapse during inhalation and exhalation. These hyaline cartilage rings are incomplete posteriorly, allowing for flexibility and the expansion of the adjacent esophagus during swallowing. The posterior part of the trachea is composed of smooth muscle (the trachealis muscle) and connective tissue, which help regulate the diameter of the airway.
- The inner lining of the trachea is composed of pseudostratified ciliated columnar epithelium with numerous goblet cells that secrete mucus. This mucociliary lining plays an essential role in trapping dust, pathogens, and other foreign particles, which are then swept upward by coordinated ciliary action toward the pharynx to be expelled or swallowed. This mucociliary escalator is a critical component of the respiratory system’s defense mechanisms.
- Functionally, the trachea serves as a conduit for air, but it also participates in air filtration, humidification, and temperature regulation before the air reaches the lungs. It provides a rigid yet adaptable passage that accommodates changes in posture, breathing patterns, and physical activity. The trachea also plays a role in cough reflexes, helping to expel irritants and secretions from the respiratory tract.
- Clinically, the trachea is a significant focus in respiratory medicine. Conditions such as tracheitis, tracheomalacia, tracheal stenosis, and tracheal tumors can impair breathing and require medical intervention. Additionally, in emergency situations where upper airway obstruction occurs, procedures such as tracheostomy (surgical creation of an opening in the trachea) or endotracheal intubation are performed to ensure airway patency and adequate ventilation.
