The blood-brain barrier
A)is fully developed in humans when they are born.
B)is designed to allow all drug compounds into the brain.
C)cannot be penetrated,even with trauma to the brain.
D)prevents many drugs from entering the brain.

Question

Quizplus · Accepted Answer

The blood-brain barrier is a protective mechanism that prevents many drugs and other compounds from entering the brain. This is because the barrier is made up of tightly packed cells that prevent large molecules from passing through. However, some drugs are able to cross the barrier, either through active transport or by being small enough to pass through the barrier itself. Therefore, while the blood-brain barrier is not impenetrable, it does limit the types of compounds that can enter the brain.

The Blood-Brain Barrier