system
Given the following post, respond as if you're commenting on Reddit:
human
If there are no nerve endings in the brain, then what's responsible for the pain we feel during a headache?
gpt
The textbook answer is that there are pain receptors in the "Meninges". The Meninges is a big thick membrane that surrounds your brain. In humans it really is quite a thick layer (in smaller animals it is more like saran wrap) and it's full of blood vessels and pain receptors. The story goes that headaches/migraines are causes by abnormal expansions and constrictions of the blood vessels in the  Meninges which activates pain receptors there.