Ethmoidbihålorna

Ethmoidbihålorna, also known as the ethmoidal air cells or ethmoid sinuses, are a series of small, thin-walled cavities located within the ethmoid bone of the skull. This bone is situated between the eyes, behind the bridge of the nose. The ethmoid bone is a complex structure that forms part of the anterior cranial fossa, the medial wall of the orbits, and the roof of the nasal cavity. The ethmoid sinuses are not a single cavity but rather a collection of numerous air-filled spaces, typically divided into anterior, middle, and posterior groups.

These sinuses are lined with a mucous membrane that produces mucus, which helps to trap dust and debris and keep the nasal passages moist. The mucus is drained into the nasal cavity through small openings called ostia. The ethmoid sinuses play a role in humidifying inhaled air and contributing to the resonance of the voice. Due to their small size and numerous connections, they are susceptible to inflammation, a condition known as ethmoiditis, which can be part of sinusitis. Blockage or infection can lead to pain and pressure in the area between the eyes and behind the nose. Their proximity to the eyes and the brain makes infections of the ethmoid sinuses a concern that requires medical attention.