1603 in science

Transcription

[MUSIC] [MUSIC] We’d like to think that we walk through our lives completely conscious, free to choose whatever we like, totally completely in control. Not even close. Our bodies leave a lot to autopilot, which is a good thing, because imagine having to regulate your heartbeat and your breathing and your digestive system and your body temperature, all while not peeing your pants or falling down. That would be hard. Many of those involuntary actions are mysterious, annoying, just plain weird. Here are five of the human body’s strangest out of control behaviors. Start typing “why does my” into Google and the top result is an eye-opener. Involuntary twitching of the muscles around the eye has a number of causes including dry eyes, caffeine, bright lights, and just like during a tough workout, from simple fatigue. It’s usually totally harmless and eventually goes away on its own and is a good hint that you’ve probably been looking at that screen enough for one day. Looking at bright light can cause more than an eye twitch. In Aristotle’s "Book of Problems" he asks “Why is it that one sneezes more after one has looked at the sun” proving that people have been asking a lot of the same questions for a long time and that no one told Aristotle that you’re not supposed to stare at the sun. Like, ever. Don’t do it. The so-called photic sneeze reflex, AKA the Autosomal Cholinergic Helio-Ophthalmic Outburst, abbreviated "ACHOO"… yes, seriously… is experienced by about 1 in 4 people, leading scientists to believe it is genetically heritable. While the exact cause hasn’t been pinpointed, many scientists think it’s due crosstalk between the optic nerve and nerve that feeds the tickling sensation in your nose. The visual cortex of sun-sneezing people is also prone to overstimulation, which might send the sneeze sensing parts of their brain haywire. Have you ever been just about to go to sleep, walking through the gates to Dreamland, only to have the floor pulled out from under you and you’re suddenly falling and then you wake up! This frustrating sleep starts have another cool medical name, hypnagogic myoclonus. When we drift off, the areas of our brain that control motor function are inactivated in favor of those that control our sleep cycles, which is why you can dream about riding your bike without actually moving your feet. As the sleepy part of your brain fight with the awake and moving parts of your brain, the battle can spontaneously tip back in favor of the motor control side and suddenly you’re like… WHOA, I'm awake. Sleep starts aren’t the only myocloni that we experience. Hiccups are an uncontrollable contraction of the diaphragm muscle that we use to draw air into our lungs. About a quarter second after that muscle contracts, the vocal cords snap shut, creating the characteristic [hic]. Scientists still aren’t sure what causes em, but possible explanations include hiccups being an evolutionary remnant from a few hundred million years ago when our ancestors still had to pump water over their gills. Or, since hiccups mainly happen in mammals, that they started as a way for nursing infants to clear air from their stomachs. If you want to get rid of hiccups, it seems that increasing the amount of CO2 in your blood can do the job, which is common remedies include drinking water, holding our breath, or breathing into a paper bag. Yawning, another long, slow, involuntary form of breathing, is common throughout the animal kingdom and even happens in the womb. We know it’s associated with sleep and boredom, but that doesn’t explain why it happens, and like most human behaviors, if you stop and think about yawning long enough it starts to become a really, really weird thing to do. Hippocrates believed that yawns released noxious fumes that had built up in the body, but modern medicine has shown us that usually happens on the other end of the body. We also know that about 50% of people who observe a yawn will yawn in response, so it’s thought to be a social cue to synchronize biological clocks. One theory says yawns might even cool the brain slightly to make us more alert as we get bored or sleepy. Even watching someone talk for extended periods of time can induce yawning, so next time you’re getting bored in class, tell your teacher it’s Mother Nature’s fault. Finally, I’ll leave you with one bonus behavior: post-micturition convulsion syndrome, or the pee shivers. This is another behavior for which scientists haven’t quite shaken out all the details, but some believe its simply because we’re exposing sensitive areas of our body to the cold while we expel some internal warmth. They might also arise from a bit of conflict between our autonomous nervous system that’s usually quietly keeping all that pee inside and the part of our conscious mind that’s in charge of the plumbing at that moment. These weird, wild, and often twitchy behaviors may defy nice, neat explanations, and yes, sometimes they are very annoying, but in the great movie that is life, they’re a nice reminder of all the amazing things going on behind the scenes. Here’s a reflex action: You click subscribe, and I’ll see you again next week. Stay curious.