Cerebrospinal fluid is fluid that's between the arachnoid mater and pia mater. Cerebrospinal fluid allows the brain to float (buoyancy) so the weight of the brain doesn’t cut off the blood supply. It also protects the brain and the spinal cord by surrounding it with structure that is cushions it. Another function of the cerebrospinal fluid is that it regulates the biochemistry by interchanging materials in the blood stream like metabolic wastes and nutrients. The blood brain barrier works by letting only certain chemical pass it barrier that's located between the cerebrospinal fluid and the blood. Since its main function is to keep out some chemicals the blood brain barrier doesnt certain chemicals of the blood to enter the brain. The chemical
