The human body is a weird and fascinating sack of bones, organs, nerves, blood and a couple other things I can't be bothered to list. But, you know, they're there.

I know I do some basic things like breathe, eat, poop, sleep... but the WHY and HOW behind the body is shrouded in mysterious scientific jargon and... probably some other stuff. Pie charts? I dunno.

Either way. It's MYSTERIOUS.

But remain calm, because all your burning questions are about to be answered in the next 6 pages.

Thanks to all the fine folks in the Redditverse that took the time to ask and answer these questions. You humans are truly heroes of the internet.

1/12. Answered by: jpsky Ratsarecool asked: Why is it that before an orgasm you have a feeling willingness to do anything, but as soon as the orgasm passes you come to your "senses"

It's because of your limbic system. It's the more animal part of your brain that controls optimal urges, like hunger, or sex. It's responsible for your fight or flight urges as well. It resides in the back of your head.

Meanwhile your prefrontal cortex, located in your forehead, is more responsible for logic and reasoning, as well as houses your morals, or your decisions about what you are and what you want to be, and behavior that is okay, and other behavior that isn't.

The more "in charge" the limbic system becomes, the less ability your prefrontal cortex has to apply reason.

And as you start down the road of sexual arousal your brain floods with chemicals, like dopamine, which reward your behavior and makes you want more. And it feeds into your more limbic desires. At some point it takes complete control and you may lose all rational thought momentarily.

But after orgasm your body...

releases tons of chemicals, some of which counteract the dopamine high you were previously on, and prefrontal cortex logic and reasoning are restored. This can lead to the feelings of guilt or shame if you went outside your normal boundaries that your prefrontal cortex decided you wouldn't previously. And it can make you even feel scared that you lost control (depends on the individual, the stronger your prefrontal cortex the stronger these feelings may be).

And it could also be that a momentary loss of control feeds into the feelings of pleasure. For some people, who feel a need to be in constant control, that moment when you feel "it's okay" to lose control let's out some pretty wild stuff. It's why BDSM is a thing. And more extreme stuff too. It's also why you see stories about autoerotic asphyxiation, people like losing control, and add to that the high feelings of oxygen deprivation, and they feed into it so much that they push it a little too far. I mean your prefrontal cortex isn't going to try and kill you. But your limbic system might if it got animal enough.

Answered by: TheDunadan29

2/12. thomhurst asked: Why does your face physically change (E.g. Get puffy or bags under the eyes) when you get little sleep?

When you don't get enough rest, the blood vessels under your eyes can become dilated, bringing them closer to the surface and causing the area underneath the eyes to swell (causing puffy eyes) and/or appear purple, blue or even blackish in color (which causes dark circles).

Answered by: MagicWade

Continue reading all the answers to your unsolved mysteries on the next page!

3/12. Schaabalahba asked: Why is it pleasurable to stay in bed an extra five minutes? Is there any physical benefit to this?

You're generally warm and comfortable, and your brain is "booting up", which mostly has to do with cranking up its metabolism and seeking glucose. In those 5-10 minutes you wake up a bit more, blood flow changes a bit, and you finish waking up completely (which is not as cut and dry a process as it may seem, ask anyone with sleep paralysis!).

There is also pleasure to be found in following a strong urge, which might involve the dopamine reward system, but I honestly don't know if this applies here.

Answered by: Aelinsaar

4/12. becauseyouhadtos*it asked: How does my body know it's time to orgasm?

Imagine a balloon.

Imagine it has tiny gates over it's entire surface that can be open or closed, but imagine them all closed, and also that they can only be open at a certain pressure lets say just double (2x) the pressure of the atmosphere and once open the will stay open until the pressure decreases back down to 1 atmosphere.

Now imagine you blow into the balloon. None of the gates are open yet but pressure is building up. 1 & 1/4 atm., 1 & 1/2 atm.

1 & 3/4 atm.

Now the gates are starting to rumble, with each breath you blow into the balloon, they can almost feel that it's time for them to open and release all of the air pressure inside the balloon.

Finally.. you blow enough air for the pressure inside the balloon to reach 2 atm.

The front velocity of the air blown by your mouth causes the gates at the back of the balloon to open first but the others follow in a wave pattern around the outside of the balloon, so that in about a full second or two, all the gates are open but you can see the wave.

The air rushes out and the balloon deflates.

Then you apologize and say we can try and inflate the balloon again in about 10-15 minutes.

Answered by: OncewasaBlastocoel

Continue reading more about weird body mysteries on the next page!

5/12. faaaabulous1867 asked: I see kids that are younger and younger with glasses every day. How do they measure how they can see and how bad their eyes are when it's literally a baby that can't even walk or talk, let alone read letters aloud from an eye exam?

Awesome question! (I'm a pediatric optometry resident)

So for children too young to give us a reliable subjective "1 or 2", we base the prescription on objective measurements. We can objectively measure their refractive error with retinoscopy (as mentioned above). That's when we shine a light in their eyes and use lenses to determine the prescription. It's very versatile, and we don't need a machine so it's perfect for kids. They can do anything (eat, watch tv) as long as their eyes are open for us to get the measurement.

In kiddos, it's best to do this when they're dilated because the dilation drops force their eyes to relax their focusing/accommodation ability (which they have a lot of). Kids can accommodate through far sighted prescription/refractive error. Prescriptions for kids under 7 should almost always be determined with dilating drops. It's normal to be a little far sighted when you're young, and as you grow up you tend to become more near sighted.

As paediatric optometrists, one of our greatest worries is amblyopia or lazy eye. That's when a child either has an eye turn, or high prescription leading them to favor one eye over the other. The non-favored eye doesn't develop the proper connections in the brain to see 20/20 because the kid will always favor his "good eye". That's why you'll see some kids wearing an eye patch. It's to force them to use their "bad or lazy eye" so the brain can recognize and developed clear vision through that eye. It's important to treat lazy eye when they're young while the visual system is still malleable.

Totorood

6/12. The_Hindu_Hammer asked: Why is it that when I wiggle my finger in my belly button, I feel it in my penis?

So, I've never experienced this, but I can give a reason from Anatomy and Embryology. During development as a fetus, the testes originate right around the level of the abdomen near the belly button. Here, they develop nerves that run to the spinal cord at this level (vertebrae T10-12, if I remember correctly).

During development, the testes move downward, travel through the inguinal canal (basically a small tunnel where your leg meets your abdomen), and descend into the testes. They remain connected to the spinal cord via the same nerves, the nerves just get longer. In the spinal cord, there's a network of nerves that integrate signals coming from the organs and the overlying skin at that area.

Those signals, 'sensation from the testes' vs 'sensation from the belly button' remain mostly separate, but there are a few overlapping connections. Because we're not really used to feeling things from our internal organs, often times our brain interprets signals coming from them as coming from the same level as that sensation. In the case of the testes, this sensation is referred to the belly button area, so often pain from the testes occurs in the belly button area (this is called "referred pain"). I suppose it's also possible that the reverse could happen as well, that sensation from the skin can be referred to the internal organs.

Answered by: BCSteve

Why do you fidget? Find out on the next page!

7/12. F--Jokes101 asked: What causes the urge to fidget?

Its a natural reaction through your nervous system little impulses and such almost like putting electricity through say a wet noodle, makes it move about.

There's also a biological and evolutionary method, basically if you sit still for too long blood begins to pool, veins and arteries are cramped and clenched... So the more you fidget the less of a risk there is for developing a blood clot. Its basically a mini survival instinct.

When its cold, fidgeting and shivering causes you to keep warm through movement and keeping your blood circulating. The reason this works is the same reason fidgeting helps you from forming a blood clot.

Answered by: ValaskaReddit

8/12. AlanSleeper asked: Why do Humans get aroused watching others having sex?

Our brains have mirror neurons, which fire both when we do thing X and when we see thing X being done by someone else. They allow us to hurt when others suffer, be happy when others are joyful, and, well, become aroused when others fuck.

Continue reading about your body on the next page! (Isn't this like grade 4 health class?!)

9/12. creepsmcreepster asked: Why do we see black spots after looking into a bright light?

The spots aren't, strictly speaking "black", they are "no signal" areas.

Sight is basically a chemical reaction. The rods and cones of your eyes produce dyes. (See "Rhodopsin" and/or "visual purple" et al.) These dyes are how your eyes see.

Photons come in, intersect, and change these dyes. This is what produces the initial chemical stimulus that becomes the nerve impulse response to light.

The photon(s) intersecting with the dyes "uses up" the dye.

Your body is constantly making new dye and cleaning up the used-up dye.

When you look at a bright light it uses up a lot of dye. Then those rods and cones don't have enough to really generate a good signal.

Similarly, if you've been in darkness for a while, you've got a lot of dye built up and you can see really well in the very dim light. Further the very dim light uses up very little dye and so you continue to see well in the dimness.

So this whole mechanism is why the room looks "darker" right after you turn off the lights, and then "your eyes adjust". It's also why the "blue spots" move with your eyeballs, because its the individual sensors that are exhausted.

Answered by: BitOBear

10/12. allboutthatlife asked: What is physically happening when your ear suddenly starts ringing?

The first thing to understand is how we perceive sound: We have outer and inner ear hair cells, and they both detect vibrations and pressure changes of the basilar membrane. The reason we have two types of hair cells is because, while vibrations travel very efficiently in the fluid of the inner ear, they require a lot of energy (think about trying to run on land vs. trying to run in a pool).

Outer ear cells, then, are designed as amplifiers. When they detect low energy vibrations, they vibrate in time with them, amplifying the signal and sending it to the inner ear. Most of the time, this system works perfectly, but - like any biological system - it can get buggy. Sometimes the outer ear cells will freak out and vibrate on their own, and that's when you get the sudden onset tinnitus. There's also a control system that will tell the outer ear hair cells to knock it off, but it takes about 30-45 seconds to kick in.

Answered by: Archchancellor

What happens when you need to fart but then it goes away? Find out on the next page!

11/12. Tinyshlo asked: What happens to a fart when you don't let it out but the need to fart goes away?

Your colon is an air tight tube. The ONLY way a fart is getting out is through the anus. When you hold a fart in, you pushing it back up above the internal anal sphincter. Pressure below the internal anal sphincter and around the external anal sphincter is that "I have to fart" or "I gotta poop" sensation. More pressure around the external sphincter leads to greater stretching of the sphincter. Greater stretching = greater urge. The fart will eventually come back down, you've just temporarily forced it further up "inside", beyond the physical point in the colon where you can feel the urge to let it out.

Answered by: Shmalpin

12/12. crazy_angel1 asked: why when you think or see very sour things, you start to salivate?

A sour taste comes from acids in the food, so it may be a response to help protect tooth enamel from being destroyed by the acid. This is why you salivate before vomiting, as well. So your brain could be deciding you're about to eat something acidic, and pumps up salivary production in response.

Answered by: MapsAreCool