Final answer:
The role not associated with cerebrospinal fluid (CSF) is the clotting of hemorrhage within the brain. CSF primarily acts as a cushion, removes waste, maintains pressure, and aids in blood perfusion, but does not contribute to blood clotting. The correct option is C.
Step-by-step explanation:
The function that is NOT a role of cerebrospinal fluid (CSF) is 'C. provide clotting of haemorrhage within brain'.
The main roles of CSF include providing mechanical protection for the brain, which means it acts as a liquid cushion for the brain and spinal cord, maintaining consistent pressure within the cranial cavity to support nervous tissue, and removing metabolic wastes from the nervous tissue.
Another important function is the facilitation of blood perfusion by managing intracranial pressure. CSF circulates through the CNS, picking up metabolic wastes and transports them out, which are then reabsorbed into the blood through the arachnoid granulations.
This process ensures the waste is filtered out and the CNS is protected from potential toxins and pathogens in the bloodstream, as mandated by the blood-brain barrier. Option C. is the correct one.