👉 The William Fluid, also known as the fluid in the central canal of the spinal cord, is a unique cerebrospinal fluid (CSF) that exhibits properties distinct from other CSF types. Unlike the peripheral CSF, which circulates through the spinal canal and is primarily involved in cushioning and nutrient transport, the William Fluid flows through the central canal at a higher velocity and is characterized by its low viscosity and specific protein composition, including the presence of the protein S100A11. This fluid is crucial for maintaining the health and function of the spinal cord, facilitating nutrient transport, and playing a role in immune responses within the central nervous system.