Hollow, air-filled cavities, especially in the bones of the skull.
The nasal sinuses, which are air-filled cavities located around the eyes and nose, possess mucous membranes similar to those found in the nasal passages. These specialized membranes produce mucus and serve multiple functions within the respiratory system. Firstly, they contribute to the purification and cleansing of the nasal passages, trapping dust, debris, and potentially harmful particles. Additionally, the sinuses play a role in enhancing the resonance of the voice, aiding in the production of sound. Lastly, these cavities provide structural support to the face, helping to maintain the shape and stability of facial features.