Cerebrospinal fluid: A clear, colorless body fluid found within the brain and spinal cord, acting as a cushion for the brain's cortex, providing basic mechanical and immunological protection.
Fourth ventricle: A chamber in the brain that lies between the brainstem and the cerebellum, playing a crucial role in circulating cerebrospinal fluid throughout the central nervous system.
Subarachnoid space: The area between the arachnoid membrane and pia mater around the brain and spinal cord containing cerebrospinal fluid, which helps protect and nourish central nervous system tissues