10 strange things your body does, and why
1. Skin gets goose bumpsThey crop up when you're scared or cold, or even while you're listening to a piece of particularly moving music (or even worse, when someone runs their fingernails across a chalkboard). But there's actually no biological reason we get them anymore. When humans were much hairier, goose bumps served as a tool of intimidation. For example, you may have noticed that when animals feel threatened, their hair often stands straight up. That's so they appear larger, and therefore more dangerous. It worked the same way for us back in the day. But now that we have much less hair than our ancestors, goose bumps are much more visible, and pretty pointless.
2. ShiverIt's like the opposite of sweating, which happens when you're overheated and need to cool down. Shivering when you're cold helps generate and preserve heat. It also helps trigger the preservation of homeostasis, which maintains the stability of your internal functions.
3. Jerk awake while falling asleepIt's actually called a hypnagogic or hypnic jerk. And one theory says it happens because as your body starts to relax and your breathing slows, your brain somehow thinks you are falling instead of falling sleeping, and it wants to make sure you're aware that hey, you might be falling to your death. Other theories maintain that it's just a normal part of relaxing, and usually occurs if you're anxious or stressed, have drank too much caffeine or alcohol, or are very fatigued. Unfortunately, the more you start to worry about them, the more you may experience them.
4. YawnContrary to popular belief, you don't yawn because you're tired or bored. New research shows that yawning may just be a way to keep your brains cool — literally. Essentially, a yawn acts like your brain's personal air conditioner. And this cooling down process helps keep you sharp and more alert in stressful situations. And yes, seeing someone else yawn or simply thinking about a yawn can, in fact, make you yawn.
5. SalivateThis happens for a number of reasons: To keep our mouths lubricated, help break down food, and (ewww!) protect our mouth and teeth before we vomit. Thinking about or see some tasty food? Your mouth will start to water in preparation for your next meal.
6. Eyes twitchIf you feel a little flutter in your lower lid, it could mean a number of things: stress, lack of sleep, dry eyes, eye strain, sensitivity to light, too much caffeine, alcohol, and allergies. Does your eye constantly twitch? Take a few minutes to look away from your computer, try to catch up on sleep, or put the coffee down. You could also be dehydrated — so take a sip of water.
7. HiccupIn order to breathe, our lungs work in conjunction with our diaphragm, a muscle that helps pull air into the lungs and relaxes to release air back out of the lungs. And if you eat or drink too quickly, the diaphragm can become irritated, which means air can get stuck in your throat and in turn, cause a hiccup. The good news: They generally last just a few minutes, and holding your breath or taking a few deep breaths can cure them fast.
8. Eyes tear upCrying is a lot more complicated than you think. There are literally different tears for every kind of situation. And they are: Basal Tears: They keep our eyes wet at all times and protect them from bacteria and other harmful stuff. You can usually go about your day without noticing basal tears. Reflex Tears: Do your eyes water when you're chopping an onion? Those are called reflex tears, which are released in larger amounts than basal tears. They occur to keep an unwanted gas or acid from penetrating your eyes. Emotional Tears: You can count on these appearing when you're really sad, happy, scared, or just feeling overwhelmed. Scientists don't really know why we cry emotional tears, except that they might have a calming effect and be an evolutionary social cue that you're sad.
9. BlushYou know the feeling: You find yourself in an embarrassing situation, and you feel a rush of heat creeping up your face. Well, that's just your body experiencing a rush of adrenaline, an increased heart rate, and dilated blood vessels to improve blood flow. Scientists believe this is an evolutionary social cue and kind of like a nonverbal apology for social missteps.
10. Belch and fartYes, they're awkward, but they happen when gas needs to be released from the body. You probably burp when you swallow too much air, eat too quickly, chew gum, or drink carbonated beverages. Stomach infections can also cause non-stop burping. On the flip side, flatulence occurs when food isn't fully digested in the stomach and small intestine, and hits the large intestine in an undigested state. Bacteria starts to feed on the food, thus creating gasses that have to come out.