Description
Four groups of air-filled spaces called paranasal sinuses (maxillary, frontal, ethmoidal, and sphenoidal) surround the nasal cavity. The sinuses are named according to the bone in which they are found. The nasal sinuses are lined with respiratory mucosa which secretes mucus into the nasal cavity. The paranasal sinuses receive nerve innervation from branches of the trigeminal nerve (CN V).
The paranasal sinuses are involved in humidifying and warming air on its way to the lungs, amplifying vocal resonance during phonation, regulating intracranial pressure, and decreasing the overall weight of the skull.
