its when air passes within 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.
4
No, they are not.
sinuses
SINUSES
sinuses
sinuses are caves in the skull that can not be removed.
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
The air-filled paranasal sinuses and their mucous tissue linings help regulate the temperature and humidify the air breathed in, lighten the bone structure and weight of the skull, and give tone to the voice. It is not entirely clear what the skull's blood-filled cranial venous sinuses' full purposes are, but they do function to help the collection and return flow of venous blood and cerebrospinal fluid drainage from the tissues and veins in the cranium and back to the heart.
Sinuses