The nose and nasal cavity is what begins the process inside the respiratory system. The nose is the organ with which we breathe air in. The nasal cavity is the are inside the nose, separated from the oral cavity (the area inside the mouth) by the nasal spine. The purpose of the nasal cavity is to deliver cleaned, moistened, and warmed air to the pharynx (throat). The cavity is lined with mucous that has tiny hairs on it. The hairs trap dust particles and other pathogens so that the air clean to pass into the next stage.