What Are the Lungs and Respiratory System?
At the top of the respiratory system, the nostrils (also called nares) act as the air intake, bringing air into the nose, where it’s warmed and humidified. Tiny hairs called cilia (pronounced: sih-lee-uh) protect the nasal passageways and other parts of the respiratory tract, filtering out dust and other particles that enter the nose through the breathed air. Air can also be taken in through the mouth. These two openings of the airway (the nasal cavity and the mouth) meet at the pharynx (pronounced: far-inks), or throat, at the back of the nose and mouth. The pharynx is part of the digestive system as well as the respiratory system because it carries both food and air. At the bottom of the pharynx, this pathway divides in two, one for food (the esophagus, pronounced: ih-sah-fuh-gus, which leads to the stomach) and the other for air. The epiglottis (pronounced: eh-pih-glah-tus), a small flap of tissue, covers the air-only passage when we swallow, keeping food and liquid from going into
