The sinuses are
O air-filled cavities that secrete mucus to keep the nose moist and remove bacteria.
O tubes at the end of the pharynx that are made of different types of cartilage and muscle, and lined with a mucous
membrane.
tubes that conduct air to the lungs, and allow for gas exchange of oxygen and carbon dioxide.
small, curved, bony plates that line the walls of the nasal cavity, and are covered with a mucous membrane.