The use of chemotherapy for brain tumors is complicated by the fact that
A) brain tumors do not respond to traditional chemotherapy.
B) chemotherapy causes too much damage to neurons to be considered as a treatment for brain tumors.
C) many substances used in traditional chemotherapy do not cross the blood-brain barrier.
D) substances used in traditional chemotherapy mimic the actions of naturally occurring neurotransmitters.

Question

Quizplus · Accepted Answer

The blood-brain barrier is a protective barrier that prevents many substances from entering the brain. This makes it difficult to treat brain tumors with traditional chemotherapy as many chemotherapy drugs are unable to cross the blood-brain barrier.

The Use of Chemotherapy for Brain Tumors Is Complicated by the Fact