What is the role of cerebrospinal fluid (CSF)?

• A. It cushions the brain and maintains intracranial pressure.
• B. It carries oxygen to neurons
• C. It metabolizes neurotransmitters
• D. It stores glycogen

Answer: (A)

Cerebrospinal fluid mainly cushions the brain and helps regulate intracranial pressure by providing buoyancy and a stable environment. The fluid surrounds the brain, fills the ventricles, and circulates in the subarachnoid space, which reduces the brain’s effective weight and protects neural tissue from impact. This buoyant support helps keep intracranial pressure within a narrow, safe range as blood volume and brain activity change. CSF also participates in maintaining the chemical balance around neurons and waste clearance, but its most direct, defining role is cushioning and pressure regulation. Oxygen delivery to neurons, neurotransmitter metabolism, and glycogen storage are handled by other systems: oxygen comes via cerebral blood flow, neurotransmitters are processed by neurons and glia, and glycogen is stored in astrocytes and other tissues, not in CSF.