The primary purpose of the blood-brain barrier is to
A)provide the brain with oxygen.
B)isolate the CNS from general circulation.
C)drain blood from the brain.
D)hook areas of the brain together.
E)None of the answers are correct.

Question

Quizplus · Accepted Answer

The blood-brain barrier is a specialized structure that isolates the central nervous system (CNS) from the general circulation of the body, preventing the entry of many substances (e.g., toxins, pathogens) that could be harmful to the brain. The barrier is composed of tightly packed cells lining blood vessels in the brain, which restrict the movement of molecules and ions across the vascular system. The oxygen and nutrients necessary for brain function are able to pass through the barrier via specialized transport mechanisms, but many other substances are blocked, including most drugs. Therefore, the blood-brain barrier plays a critical role in protecting the CNS and maintaining homeostasis.

The Primary Purpose of the Blood-Brain Barrier Is to