Which structure gives the CNS a privileged blood supply?

1. It restricts what can enter the CNS. 2. Drug design must work around it. 3. The CNS has a privileged blood supply, as suggested by the blood-brain barrier. 4. So the answer is the blood brain barrier. _Source: OpenStax 'Anatomy and Physiology 2e', Ch 13 'Anatomy of the Nervous System'_