Final answer:
The glial cells that line the central cavities of the brain and spinal cord and help to circulate cerebrospinal fluid are ependymal cells.
Step-by-step explanation:
The glial cells that line the central cavities of the brain and spinal cord and help to circulate cerebrospinal fluid are ependymal cells. Ependymal cells are responsible for filtering the blood to produce cerebrospinal fluid, which cushions the neurons and performs some of the functions of blood in the brain and spinal cord. They line the fluid-filled ventricles of the brain and the central canal of the spinal cord.