What is the primary function of cerebrospinal fluid?

The primary function of cerebrospinal fluid (CSF) encompasses both the protective and nourishing roles it plays for the brain and spinal cord. CSF is a clear fluid that surrounds the brain and spinal cord, providing a cushion that protects these critical structures from injury due to impact or sudden movements. This cushioning effect is vital in preventing trauma to the sensitive neural tissues.

In addition to protection, cerebrospinal fluid is also important for nourishment. It facilitates the exchange of nutrients and waste products between the brain and the blood, thereby playing a crucial role in maintaining the optimal environment for neuronal function. It helps regulate the chemical composition of the extracellular fluid in which neurons reside, supporting their metabolic needs and removing waste products.

Given these dual functions, the comprehensive answer is that cerebrospinal fluid not only serves to protect the brain and spinal cord but also contributes to nourishing them, which is why the choice indicating both of these functions is the correct one.