Paranasalisten

Paranasalisten, commonly known as the paranasal sinuses, are a group of air-filled cavities located within the bones surrounding the nasal cavity. They are lined with a mucous membrane and connected to the nasal cavity by small openings called ostia. The sinuses contribute to humidifying and warming inhaled air, producing mucus, and helping to reduce the weight of the skull. They may also influence the resonance of the voice.

The paranasal sinuses are organized into four paired groups: the maxillary sinuses (the largest, located in the maxillary bones), the frontal sinuses (in the frontal bone above the eyes), the ethmoid sinuses (a network of small air cells within the ethmoid bone), and the sphenoid sinuses (in the body of the sphenoid bone behind the nasal cavity). Each group has its own drainage pathways into the nasal cavity, primarily through the middle and superior meatuses. The maxillary and frontal sinuses drain into the middle meatus via the ostiomeatal complex, while the anterior and middle ethmoid air cells drain into the middle meatus and the posterior ethmoid air cells drain into the superior meatus. The sphenoid sinuses drain into the sphenoethmoidal recess.

Development progresses through childhood, with the frontal sinuses typically enlarging during adolescence. The exact functional significance of the sinuses remains a topic of discussion, but they are generally regarded as supporting functions such as airflow regulation, voice resonance, and immune defense through mucus production.

Clinical relevance centers on rhinosinusitis (inflammation of the sinuses), which can be acute or chronic and is characterized by facial pressure, nasal discharge, and reduced sense of smell. Diagnosis commonly involves clinical evaluation and imaging, such as CT, while treatment includes decongestants, saline irrigation, antibiotics when indicated, and sometimes endoscopic sinus surgery to restore drainage.