12 Of Life's Most Confusing Biological Mysteries Explained So Even A Child Could Understand.

You know what? Life is complex. And the more you think about it, the more you realize you DON'T actually understand most of what goes on with even something so intimate as your own body. You've been walking around in this thing for HOW LONG? Well, let us start with some of the most basic of biological mysteries.

Thanks to all the awesome folks over at Reddit who provided answers to these!

1/12. AmericanPixel asked: Why do men appear to have a "stitch line" or "scar line" at the base of their ballsac?

Saying it "started out as a vagina" is an overstatement, but it's grounded in truth.

When we're forming in the womb, we start with a shallow slit between our legs. For women, that slit deepens while in men it stitches together.

The left side is grown, the right side is grown, and then they fuse together. Later, the testes descend into them.

Calling it a vagina at that stage in development isn't really accurate; a vagina is more than just a gap in skin, it's a structurally complex organ with a dozen different unique cells and its own intricate biology. The prenatal gap superficially, however, is closer in appearance to a vulva than to testicles, hence the common narrative that we all start as women.

Submitted by ManualNarwhal & Notmiefault

2/12. DoTheLaLaLaLaLa asked: Why does your appetite decrease in extreme heat?

Your metabolism's job is to regulate the temperature of your body. "Metabolizing" food is basically like setting it on fire in your body and using the heat for energy.

In the extreme heat, your body temperature is already high. So your body doesn't burn the energy it has as aggressively (your metabolism slows down) so that you don't overheat. This decreases your appetite.

It's also why you have less energy and feel wiped out after a hot day. You still needed that energy, but your body converted less to avoid overheating. Basically put you in low power mode.

Submitted by bkanber

Read about even wilder biological mysteries on the next page!

3/12. LebumGermsJr asked: Why does a hangover get worse as we age?

Alcohol is metabolized by liver enzymes and first broken down into acetaldehyde - which is our hangover culprit. After that, it is broken down by an enzyme into acetate which eventually turns into carbon dioxide and water. All are then washed out along with sins from the night before...

The number of enzymes used in this two step metabolism process slowly dwindles as we age, making us less and less efficient at processing the toxins. This means that the asshole acetaldehyde hangs around longer in our aged bodies that it did before, making us feel like we're slowly dying.

Submitted by marriedtodata

4/12. Elocmada asked: Why does adrenaline in certain circumstances give people super human strength? (Being able to lift extremely heavy things off of people, etc.)

They can't test hysterical strength, so we can only hypothesize why adrenaline causes it. More than likely it is because your muscles are under several inhibitory systems, including pain as well as the neurological restriction of simply having not enough signaling at any given time to activate all the muscle fibers in a group. Strength isn't just about raw strength, its about timing; you need one perfectly timed electrical burst to signal all fibers to work in concert when exerting force. The more fibers activated simultaneously, the more strength you'll have.

Adrenaline most likely acts to remove several different limiter systems. Your pain sensation is dulled or removed entirely, your blood vessels are dilated and your muscles are more heavily oxygenated, and your neural activity increases; more brain activity = increased signalling, which means you're better able to activate more muscle fibers at once.

The reason we can't do this all the time is fairly obvious - it puts much more strain on the body and consumes far more energy. Since our bodies evolved in times of scarcity, our bodies evolved a logical mechanism for limiting the bodies ability to use its full strength and energy; only when the brain sensed certain stimuli (a tiger, a child in trouble), would it release its natural chemicals that overrode its own internal limiters, allowing for a brief state of higher muscle performance.

Submitted by ninemiletree

More mysteries solved on the next page!

5/12. Consinneration asked: Why is it that when you get hit (I.e. bang your head on a corner) you instinctively apply pressure with your hands? Why does that seem to help?

Your body can only process so much sensation at once. By touching the place that you've hurt, you're basically distracting your brain from the sensation of pain by introducing pressure.

It's another reason why ice packs can help with pain - not only do they reduce swelling, they introduce the cold sensation and give your brain something else to think about other than the pain.

Submitted by BindweedHawkmoth

6/12. mystriddlery asked Why do we forget dreams so quickly?

Think of your brain like a computer. It has different types of memory like a computer. When you are dreaming, the dreams are using the part of your brain that is like RAM to a computer. It is only stored there temporarily until you wake up. Your brain basically shuts off all memory parts of your brain while it is sleeping. You experience them as you sleep but once you wake up they never get put into storage, so it's like they never happened.

Submitted by SparkleLush

Continue reading answers to your burning biological questions on the next page!

7/12. bomb_relief asked: Why do we get this "spacey" feeling right before we sneeze?

A sneeze is an involuntary action but it is a semi-autonomous one, meaning you have some degree of control over it. Most of the time, though, you don't choose to exercise this control and resign yourself to the action. It's similar to a yawn- you feel your own body doing something on its own accord. Additionally, your breath fluctuates wildly during a sneeze and especially during multiple sneezes. This combination- your conscious brain experiencing an unconscious action plus a change in your regulation of oxygen- creates a "disconnected" feeling that leaves you feeling discombobulated after a sneeze, as if you're "returning to reality".

Submitted by fatstupidbaby

8/12. thegodofwine7 asked: How does mental or emotional stress manifest with different physical symptoms (i.e. pimples, nausea, panic attacks, etc.)?

When you are faced with danger, the threat of danger, or sometimes, even the idea of danger, your body reacts with what is called the "fight or flight" response, which I'll call the stress response. Stress is a threat to your well-being, so your body perceives this as danger.

Your body prepares itself to protect you. It does this by releasing a hormone, epinephrine, aka adrenaline, into your bloodstream. Adrenaline constricts your veins and arteries, as well as increases your heart rate and breathing rate, so that oxygen rich blood can be delivered. It also diverts bloodflow away from the digestive system since its not terribly important right now (this causes the nausea). This is to prepare you to either fight the danger, or flee from it. Either way you're going to need lots of oxygen delivered quickly to your muscles.

When your body reacts to mental or emotional, rather than physical stress, it still reacts the same way. Quick anecdote - I suffer from anxiety. About a year ago, I was in a bus accident and got thrown across the bus. It was terrifying (mental stress) and I did a pretty wicked faceplant (physical stress). What I noticed was that my physical reaction was almost identical to a panic attack I had a few months earlier.

Basically, your body is preparing you for some kind of physical throwdown when you're stressed. But, there's nothing to fight, especially when it's something like an essay that's half done and due in three hours, so you just have to ride out the adrenaline. So, you get a racing heart, hyperventilation, numbness in the fingers and toes, nausea, inability to stay still.

Submitted by midnightpatches

Continue reading about even crazier biological mysteries on the next page!

9/12. J4ckrh asked: If smell is based off your nose reacting to particles, how do predators like sharks smell, for example, "a single drop of blood from over two miles away"?

They can't until some of the particles travel the 2 miles to reach them. But they can detect very low concentrations of particles, so it doesn't take much for them to notice it, and then they can locate the source.

Submitted by rigamortus76

10/12. junmilreyso asked: Why do primitive animals/species know how to animal/specie by themselves, while us humans have to be taught since birth almost everything?

Actually, humans are born with the innate knowledge and ability to survive as is necessary for a baby. We're born with a suckling instinct, for example, to latch onto nipples and draw food. We also have all the autonomic reflexes already, such as ticklishness, breathing, heart rate regulation, etc. These are common to all mammals, of which we are a member.

This is because primates are social animals; we are born into a group collective (a family unit) and predictably have a social group to learn from. You have to remember that when it comes to survival, humans know everything they need to know right when they're born, because all that is required of them is autonomic in nature (breathing, heart rate, feeding, urinating, defecating, sleeping, waking), and we only require more complicated systems when we've grown. Humans as a whole are very weak when they're first born, and require a great deal of security for quite a long time, compared to other animals. This is likely because we devote such a great percentage of the nutrients we ingest in order to develop our brains, as opposed to most other animals needing only to develop their bodies. This is likely why parents have an overwhelming emotional bond with their children.

Some animals are not social, and are therefore unable to learn from others of their species, and so they're born with (or learn shortly after birth) more complex instincts.

Submitted by Kotama

More learning to be done on the next page!

11/12. Narksdog asked: If our body creates memory cells for immunity after we have an infection or virus, how come cancer survivors are more likely to contract cancer again and die from it?

Cancer isn't bacteria or virus, it's you body's own cells malfunctioning. Normally your immune system can notice when cells are reproducing uncontrollably, but not always. They are your cells, not foreign bodies.

Even when tumors get destroyed, there are often still rogue cancer cells floating around in your blood that get missed. They're just too tiny to catch all of them, usually, so there is a chance they'll re-implant somewhere down the line and begin reproducing again, growing a new tumor.

Submitted by slackador

As slackador said, you don't 'catch' cancer because it's not an infection. Your body produces malfunctioning, potentially cancerous cells all the time because of random defects occurring during DNA replication or because of environmental factors. They will all be different and the majority of them will be destroyed by your immune system or spontaneously die because they have detected their own defect.

Submitted by Aponomikon

12/12. Donezoo69 asked: How do we get diarrhea, and why is all liquidy??

Diarrhea is the result of stool passing through the large intestine too fast and the intestine not being able to absorb all the water. Causes vary from infection, to nervousness, to too much fiber. Also, it depends on how what you're consuming reacts with your body. Alcohol causes some people to get diarrhea because it irritates the stomach lining and your body pushes it through the intestines faster, same thing with spicy foods. Capsaicin reacts poorly with a lot of stomachs and the body doesn't always break it down hence fire poops. Also, there's things like IBD and IBS.

Submitted by cant_afford_gas

Breaking up is hard to do.

And when you get the law involved, it's even worse. But sometimes people don't need the law's help to make things overcomplicated, they just have a grand ole time making that happen themselves.

People on the front lines of human cruelty include divorce lawyers. These are their stories.

Keep reading... Show less