字幕表 動画を再生する 英語字幕をプリント This business you've got going on up here... is a mess. No, you look fine! I'm talkin' about all the nerves and blood vessels that you have crammed into your face. The trouble with your face is that you have all of your major sensory organs just right there, within a few centimeters of each other, and they're all situated right around your brain. Now that's handy; short paths for communication and everything. But it also means that they all feed into the same major nerves and blood vessels that lead right in to your gray matter. This can lead into a lot of crossed wires; stimuli that are sensed by one organ can accidentally trigger another. This is why bright light can sometimes make you sneeze or a plucked nose hair will make your eyes water. And it's also what causes the brain freeze, aka The Ice Cream Headache! It's a real thing and doctors have a real name for it: spenopalatine ganglioneuralgia. Because brain freeze wasn't good enough. About a third of people are particularly susceptible to this kind of nerve pain, and it happens whenever you ingest a lot of something really cold, like a frozen treat, too quickly. When that frozen stuff hits the roof of your mouth and the back of your throat, it shocks the one spot that you really don't want to shock: the place where two of your brain's most important blood suppliers meet, the internal carotid artery, which feeds blood to your whole brain, and your anterior cerebral artery, which runs up along the front of your brain and sits right on the brain tissue. When the junction of these arteries gets too cold, they start to rapidly contract. So the brain sends extra blood there to try to warm them up again, which makes the blood vessels expand really quickly. All this contracting and expanding triggers pain receptors in the outer covering of the brain, called the meninges, where those arteries meet. But even though the pain is actually being triggered around the base of your brain, the pain signal has to travel through the biggest nerve in your whole head, the trigeminal nerve, which is responsible for ALL of the sensation in your face. The result is that the pain is actually felt somewhere else, usually in the forehead or on the top of the head, or behind the eyes. Just another care of crossed wires! Some neurologists are actually studying the dynamics of brain freeze so that they can better understand other kinds of nerve pain, particularly migraines. Because migraine sufferers tend to get ice cream headaches more often than other people. But I'm happy to report that THERE IS A CURE! Well, first you could just wait for second; it'll go away. But if you happen to have your brain frozen, just drink a little warm water, or even faster, stick your tongue up against the roof of your mouth. As soon as it warms up, you'll be ready to eat that second scoop. Thanks for asking, and thanks to all of our Subbable subscribers who keep these answers coming. They also get them a little earlier than the rest of you. If you have a quick question, let us know on Facebook or Twitter or in the comments below, and don't forget to go to youtube.com/scishow and subscribe.