The trachea is a respiratory pathway that funnels air towards the lungs, while the esophagus is a digestive organ that carries food to the stomach, according to HowStuffWorks. Food passing through the digestive tract to the esophagus can accidentally enter the trachea, making the airway feel blocked. As a preventive measure, a flap of flexible tissue, known as the epiglottis, covers the trachea opening when food is swallowed.
The trachea is positioned directly in front of the esophagus, and both organs extend from the neck to the chest cavity. The 6-inch-long trachea mainly functions as a bridge between the larynx, or voice box, and the lungs, according to the Encyclopaedia Britannica. The trachea splits into two pathways called bronchi, and these tubes enable airflow to the left and right lungs.
At 8 inches, the esophagus is slightly longer than the trachea, WebMD states. Instead of an epiglottis, the esophagus has rings of strong muscle tissue at each end, known as sphincters. The sphincters constrict and contract to let food enter the esophagus from the pharynx and exit into the stomach.
Structurally, the esophageal tube is made up of muscular walls that push food along using a wavelike contracting motion, says the Encyclopaedia Britannica. By contrast, a column of cartilage rings wraps around the tracheal tube, giving it a slightly flexible structure. On the inside, the trachea is lined with a mucous membrane covered in thin fibers called cilia, which capture harmful particles to keep the airway clean.