👉 The Os fluid, also known as cerebrospinal fluid (CSF), is a clear, colorless, and slightly yellowish liquid that circulates within the central nervous system (CNS), specifically around the brain and spinal cord. It serves several crucial functions, including providing a protective cushion that shields the delicate neural tissues from mechanical shocks and impacts, maintaining a stable environment by regulating temperature and nutrient supply, and facilitating the removal of waste products. The fluid is produced primarily by the choroid plexus in the ventricles and is continuously reabsorbed into the bloodstream through the arachnoid villi, ensuring a dynamic balance essential for optimal brain function.