The Cranium and Its Parts

22 separate bones make up the cranium or skull. A common misunderstanding is that the cranial bones grow together as we age. Except for trauma or a rare condition, these bones continue to move throughout life. Ideally they should move in a rhythmic fashion.

The entire cranial vault and spinal canal are lined with a flexible, strong membrane. This membrane divides the right and left hemisphere as well as the upper brain from the lower brain. It is the container for the cerebrospinal fluid (CSF); which is similar in chemical content and thickness to blood plasma.
CSF cushions, feeds and eliminates waste for the brain and nerves. Because CSF fills the container from the brain down the spinal canal (the tube holding the spinal cord) to the tailbone, it needs to be circulated. As CSF is produced in small cavities in the brain, called ventricles, pressure builds causing the dura sack to stretch. When the dura is stretched to a specific point, a signal is sent to the brain to stop making fluid. At the same time, the blood vessels in the cranial vault absorb fluid.  When the stretch reduces, another signal tells the brain to make more fluid, and the cycle starts again.

When the circulation of CSF is impaired, numerous disturbances can occur. Some examples are headaches, migraines, problems involving
hearing, seeing, smelling or tasting, nervous disorders and hormonal imbalances.