A chamber within a bone normally filled with air is a .?

A chamber within a bone normally filled with air is called a sinus. Sinuses are cavities that help reduce the weight of the skull, assist in voice resonance, and provide a buffer against facial trauma. They are lined with mucous membranes that help filter and humidify the air we breathe. The most well-known sinuses are the maxillary, frontal, ethmoid, and sphenoid sinuses.