Final answer:
Cavities within the brain containing cerebrospinal fluid are called ventricles, which are part of the ventricular system that produces and circulates CSF.
Step-by-step explanation:
The cavities within the brain containing cerebrospinal fluid (CSF) are called ventricles. These ventricles are part of a larger system known as the ventricular system, which includes the choroid plexus, where CSF is produced through the filtration of blood. Cerebrospinal fluid serves as a cushion, providing mechanical and immunological protection to the brain and spinal cord, and is involved in the removal of metabolic wastes.
The constant production and circulation of CSF through the ventricular system, the subarachnoid space, and eventually its reabsorption into the bloodstream are crucial for maintaining a healthy central nervous system (CNS).