Answer :
Final answer:
The blood-brain barrier is a crucial protective mechanism in the central nervous system that selectively allows essential molecules to pass while preventing harmful substances from entering.
Explanation:
Blood-brain barrier is a vital protective mechanism in the central nervous system. It consists of tight cell junctions in the endothelia lining the blood vessels serving the CNS, limiting the passage of harmful substances.
The blood-brain barrier selectively allows essential molecules like water, glucose, and gases to cross while preventing the entry of toxins and pathogens from the bloodstream.
This barrier plays a crucial role in protecting the brain and spinal cord health by maintaining a secure environment that supports the proper functioning of the central nervous system.
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