The trachea is a foundational component of the respiratory system, serving as the main airway for gas exchange. This tube-like structure connects the upper airway to the lungs, providing an open passage for air. It extends downward from the larynx, or voice box, and branches deep within the chest cavity.
The Common Name for the Trachea
The most widely recognized alternative term for the trachea is the “windpipe.” This common name is descriptive, reflecting the structure’s function as a dedicated conduit for air traveling to and from the lungs.
The trachea is also a component of the tracheobronchial tree, the collective term for the series of airways that distribute air into the lungs. In a medical context, procedures involving the trachea use the prefix “tracheo-,” such as in a tracheostomy, a surgical opening created to aid breathing.
Anatomy and Position
The trachea is a cartilaginous tube that begins just below the larynx, specifically at the lower edge of the cricoid cartilage. In an adult, the tube is roughly four to five inches long and about one inch in diameter, extending through the neck and into the chest cavity. It terminates by dividing into the right and left main bronchi at a point known as the carina.
A distinctive feature is its structure, which includes 16 to 20 C-shaped rings made of hyaline cartilage. These incomplete rings provide rigidity, preventing the tube from collapsing during breathing. The open, or posterior, side of the “C” faces the esophagus, which carries food to the stomach. This arrangement allows the esophagus to temporarily expand when swallowing large food items.
Essential Function in Breathing
The primary role of the trachea is to act as a clear passageway for air. It transports oxygen-rich air from the upper respiratory tract down to the lungs and carries carbon dioxide-rich air back out.
Beyond conducting air, the trachea also has an important protective function for the lung tissue. The inner surface is lined with a mucous membrane containing specialized cells that secrete mucus and hair-like projections called cilia. This combination forms the mucociliary escalator, a self-cleaning system that continuously traps and sweeps inhaled dust, debris, and pathogens upward toward the throat. The trachea also aids in regulating the temperature and humidity of the air before it reaches the lungs.