sivuontelot

Sivuontelot, also known as paranasal sinuses, are air-filled cavities located within the bones of the skull. They are connected to the nasal cavity by small openings. Humans have four main pairs of paranasal sinuses: the frontal sinuses above the eyes, the maxillary sinuses in the cheekbones, the ethmoid sinuses between the eyes, and the sphenoid sinuses deep within the skull behind the eyes.

The primary functions of the paranasal sinuses are not fully understood, but they are believed to contribute to several processes. They lighten the weight of the skull, act as resonating chambers for the voice, and may help warm and humidify inhaled air. The mucus produced by the sinus lining helps trap dust and other particles, which are then swept away by cilia.

Inflammation of the paranasal sinuses is a common condition known as sinusitis. It can be caused by infections, allergies, or irritants, leading to symptoms such as nasal congestion, facial pain or pressure, and a reduced sense of smell. Sinusitis can be acute, lasting for a few weeks, or chronic, persisting for longer periods. Treatment typically involves addressing the underlying cause, which may include decongestants, nasal corticosteroids, or antibiotics for bacterial infections.