Any bone except the skull.
The cranial cavity is the primary cavity of the skull; it contains the brain. In addition, the skull has four other pairs of cavities called sinuses. They are the frontal sinuses, maxillary sinuses, sphenoid sinuses, and ethmoid sinuses.
No one knows exactly what purpose the cranial venous sinuses serve in the skull. The para-nasal sinuses help to add humidity and warmth to the air that is breathed. They also lighten the weight of the skull.
its when air passes within the skull
No, they are not.
sinuses
SINUSES
sinuses are caves in the skull that can not be removed.
sinuses
Frontal Sinuses.....
M. E. Wigand has written: 'Endoscopic surgery of the paranasal sinuses and anterior skull base' -- subject(s): Endoscopic surgery, Endoscopy, Paranasal sinuses, Skull, Skull base, Surgery
Sinuses