beyond providing you with a back
We’re all idiots. It takes less than three minutes of driving down the road to realize most people don’t hold their own safety in high regard. It’s easy to get lost in the eighth level of Candy Crush and forget that we’re always almost dead. It’s a good thing our bodies have developed a series of systems to stave off destruction.
- Diarrhea Protects Us
It might not seem like a gift when you’re white-knuckling the toilet seat, but diarrhea can actually save you from something worse. Some scientists made a bunch of mice shit their pants (for science!) and paid special attention to the intestinal wall. Your intestines snake through you like a gross sock, but the permeability (i.e. how porous it is) can change. The cells along the wall allow gaps for certain things to escape the tube and enter your body. Likewise, when they detect some nasty bacteria, they close up the gaps on the inside, open up the outside, and create a super fun waterslide for the bacteria to rush out the back door.
2. Our Ears Keep Us from Falling Over
It’s amazing we don’t fall over every second of every day. Look at a baby trying to learn how to walk. All that falling makes sense. At some point, you get your feet underneath you and gravity shuts up and gets in the back seat. But surely there’s a better explanation than that, right? There is. And a lot of it has to do with your ears.
Your vestibular system (science-talk for “what makes you stand good”) is a network of signals from your ears, eyes, muscles, and joints. Your ear is split into three parts which work exactly like the levers on a forklift. One section deals with the up and down, another does the side-to-side, and the last does the forward and back. Ear goop rubs against hair (ew) while you move and your brain knows where you are. This is why spinning in a circle for a while makes you feel like the world is exploding. This ear goo/hair system teams up with your knees and feet to give your brain a sense of spatial reasoning, and then boom you’re doing the moonwalk.
3. Our Brain Blocks Out the Bullshit
We have five senses that are constantly relaying information about the sunburn on your bald spot, the lingering cheeseburger taste in your mouth, and the beautiful deer jumping into traffic.
There’s a thing in your head called the thalamus that is basically the town square when it comes to sensory information. All roads lead to the almighty thalamus. From there, the information is directed to the cerebral cortex which is essentially your brain’s TV screen. Say, for instance, you’re watching a hockey fight. There’s the punching, the screaming all around you, the dull thwack of knuckles meeting cheeks, lights, crowds, stimulation!!! There’s a lot going on. You couldn’t possibly pay attention to all of that at once without your brain overheating, so your cerebral cortex sends a signal back to the thalamus that says, “Just the two dudes punching each other, please.” The thalamus salutes the cortex and holds all the other crap behind.
4. Our Throats Close and Our Blood Stops Underwater
Have you ever wondered why the kid on the cover of Nevermind looked happy and alive instead of bummed and dead? You can thank the Mammalian Diving Response for that.
The baby’s windpipe by the vocal chords spontaneously closes to prevent water from entering the lungs. This reflex is initiated as soon as there is contact with water. However, it disappears when the child reaches the age of roughly six months, so your kid better soak it up while he/she can.
Our bodies understand that suffocating sucks, so there are some built in responses to a lack of oxygen just in case you happen to forget it. Your heart rate slows down (up to 50% by trained professionals), and blood flow to the limbs reduces in order to save it for the juicy (and more important) organs.
5. We Have Two Brains
At this moment, right now, as you’re reading this, you have between three and five pounds of bacteria in your gut.
Before you grab a knife from the kitchen and seppuku yourself, know that growing pile of aliens inside of you is actually helping. Not only does the little society of gross things inside your stomach help digest food and absorb nutrients, it can also affect your emotions.
These friendly bacteria live in harmony with more neurons than can be found in your nervous system or spinal cord. This is referred to as the “second brain.” Although it’s not going to help you with your math homework or tell you where you put your pants, your second brain helps with the complicated system of digestion and nutrient absorption. It operates independently from the brain in your skull and has its own reflexes and senses.
Those so-called “butterflies in your stomach” are possibly signals from your other brain, which is right next to your shit.
6. We’re Ready for an Attack at Summer Camp
Getting a bad night of sleep in a new place isn’t due to unwashed sheets at the Holiday Inn, or your cousin pissing the bunk bed above you at the family cabin (although those things certainly don’t help), it’s because only half of your brain goes to sleep.
The First-Night Effect keeps you alert and ready for an attack. Evolution imbued us with a never-ending fear of being eaten and it’s gone so far as to ruin your first night of sleep on your honeymoon. After the first night, your brain realizes tigers or pirates aren’t going to jump out of the closet and cut your head off so it allows both sides to rest. So if you have to perform a life-saving surgery or testify before the court in a different city, it might be best to give yourself an extra day of preparation beforehand.