Which part of the respiratory system contains the vocal cords?

The larynx is the part of the respiratory system that contains the vocal cords. It is often referred to as the "voice box" because it is responsible for producing sound during speech. The vocal cords are two folds of tissue located within the larynx, and they vibrate as air is pushed through them by the lungs, producing sound.

Furthermore, the larynx serves several important functions: it not only plays a crucial role in phonation (the production of sound) but also acts as a protective mechanism for the airway. When swallowing, the larynx elevates to prevent food or liquid from entering the trachea and lungs, helping to protect the respiratory tract from aspiration.

In contrast, the trachea is the airway that carries air from the larynx down to the bronchi, while the pharynx is the passage that connects the nasal cavity and mouth to the larynx and esophagus, serving as a pathway for both air and food. The bronchi are the large air passages that branch from the trachea into the lungs. None of these structures contain the vocal cords or play a direct role in sound production like the larynx does.