I want to know the answer to the following question:
The blood-brain barrier is made up of what?
All the background I'm provided with is that "The cells in the blood vessel walls are joined tightly to one another, forming the blood–brain barrier, which blocks the passage of many toxins and pathogens (though at the same time blocking antibodies and some drugs, thereby presenting special challenges in treatment of diseases of the brain).". Is that enough to answer the question?
Answer: yes