Your brain and spinal cord are covered by a series of tough membranes called meninges , which protect these organs ( brain and spinal chord ) from rubbing against the bones of the skull and spine. For further protection, the brain and spinal cord float in a sea of cerebrospinal fluid within the skull and spine.
This cushioning fluid is produced by the choroid plexus tissue, which is located within the brain, and flows through a series of cavities (ventricles) out of the brain and down along the spinal cord. The cerebrospinal fluid is kept separate from the blood supply by the blood-brain barrier.
As you have are more than likely already aware , your brain is a complex, highly organized organ that governs everything you do.