Which of the following is NOT a function of CSF?

• A. Cushions delicate neural structures
• B. Transports nutrients and waste products
• C. Regulates chemical substances in CSF at the blood-CSF barrier
• D. Conducts nerve impulses

Answer: (D)

CSF creates a protective and nourishing environment for the brain. Its main roles include cushioning delicate neural tissue, transporting nutrients and clearing waste, and helping regulate the chemical milieu near neurons by maintaining substances at the blood-CSF barrier. The conduction of nerve impulses, however, is carried out by neurons themselves—the rapid movement of ions across neuronal membranes and synaptic signaling. CSF provides the medium for nutrient and waste exchange and helps stabilize the brain’s environment, but it does not transmit electrical impulses.