What is the fluid that surrounds the brain?

The fluid that surrounds the brain is cerebrospinal fluid, which plays a critical role in protecting the brain and spinal cord. This clear, colorless fluid is located in the subarachnoid space and is produced by the choroid plexus within the ventricles of the brain.

Cerebrospinal fluid serves several important functions: it acts as a cushion, providing a protective layer that helps to prevent injury from impacts; it maintains stable pressure within the cranial cavity; it aids in the delivery of nutrients to the brain and the removal of waste products; and it ensures a consistent chemical environment for neural function.

Other fluids mentioned, such as synovial fluid, are found in joint cavities and function primarily to lubricate and reduce friction between the surfaces of the joints. Interstitial fluid is the fluid that fills the spaces between cells in tissues, playing a role in nutrient and waste exchange. Blood plasma, the liquid component of blood, transports cells, nutrients, hormones, and waste products throughout the body. Each of these fluids has specific locations and functions that do not relate to the protective and supportive role of cerebrospinal fluid for the brain.