| The upper airways of birds and mammals serve to transport air to the exchange areas of the lungs. Along the way the air is warmed, filtered, and humidified. The epithelia lining the airways is specialized to secrete mucus and move it toward the pharynx. Sensory receptors along these airways are responsible for our sense of smell and also help protect the respiratory system from damage via the cough and sneeze reflexes. For some mammals the evaporation that occurs in the airways is an important means of temperature regulation. In many species airflow vibrates specialized structures to produce sounds for communication. |
