Paranasal sinuses are a group of air-filled cavities located within the bones surrounding the nasal cavity. The four main pairs of paranasal sinuses include the frontal, ethmoidal, sphenoidal, and maxillary sinuses.
These structures are lined with mucous membranes and are connected to the nasal passages.
Paranasal sinuses contribute to the resonance of the voice, reduce the weight of the skull, and provide insulation for the eyes. They are also involved in regulating the temperature and humidity of the inhaled air and play a role in immune defense.
