Now, in order to prevent food from actually entering our trachea, the opening of our larynx actually contains a cartilage flap we call our epiglottis. So the epiglottis is open when air passes in, but it closes when we swallow food into our esophagus, into our pharynx. So air enters the body via the nose in the nasal cavity, a layer of mucous membrane acts as a filter and traps pollutants and other harmful substances that are found within the air that can ultimately end up in our lungs. Next, air moves into our pharynx. This is the tunnel that contains our intersection between the esophagus, the pipe that allows our food to move into our stomach, and our larynx, the connection between our pharynx and our trachea. Now, the opening of the larynx has a special flapper of cartilage we call our epiglottis, and this allows the movement of air, but does not allow the movement of food into our air passageway we call the trachea.