The larynx is an air channel between the trachea and oropharynx that plays a role in sound production. The muscles move some cartilages concerning others, increasing or reducing the opening of the rima glottis and the stress on the vocal folds (cords). Vibrations of various wavelengths are produced in the passing air, and sound is formed. It has vocal folds, which regulate the passage of air via the larynx.

The trachea is a flexible air tube that connects the larynx to the thorax. Its primary role is to act as an air conduit. A series of C-shaped hyaline cartilages layered on top of one another provide a supporting structure that keeps the trachea lumen open. The tracheal wall is divided into four distinct layers: mucosa, submucosa, cartilaginous layer, and adventitia.

The terminal air chambers of the respiratory system are known as alveoli.  Their septa serve as points for gas exchange between the air and the body as well as the blood.  The lung alveoli enhance the surface area accessible for gas exchange.