etmoidabihålorna

The ethmoidal sinuses, known in Swedish as etmoidabihålorna, are a complex group of air-filled cavities located within the ethmoid bone. This bone is situated between the eyes and forms part of the nasal cavity and the anterior cranial fossa. The ethmoidal sinuses are unique because they are not a single cavity but rather a collection of small, thin-walled cells, typically numbering between three and eighteen on each side. These cells are further divided into anterior, middle, and posterior groups, each with its own drainage pathway into the nasal cavity.

The anterior ethmoidal cells usually drain into the anterior part of the middle meatus, while the middle ethmoidal cells often drain into the middle meatus as well, sometimes directly into the ethmoidal bulla. The posterior ethmoidal cells typically drain into the superior meatus. This intricate arrangement means that inflammation or infection within one group of ethmoidal sinuses can easily spread to others or to adjacent structures.

The ethmoidal sinuses play a role in humidifying and warming inhaled air, as well as contributing to the resonance of the voice. Their proximity to critical structures like the orbits (eye sockets) and the brain makes them a common site for complications arising from sinusitis. Conditions affecting the ethmoidal sinuses can lead to symptoms such as facial pain, nasal congestion, and sometimes visual disturbances if pressure is exerted on the optic nerve. Diagnosis often involves imaging techniques like CT scans.