10 Everyday Things We Still Don't Understand About The Human Body

Here are 10 mysteries about the human body.

 Medical science has advanced in ways that were at one time likely deemed impossible. Nonetheless, there are still a number of pretty normal features and occurrences that continue to go unexplained.
Here are 10 mysteries about the human body.
Number 10. Hiccups. Other than to make people uncomfortable, hiccups do not appear to serve any purpose. It’s believed that the involuntary muscle action may be a weird evolutionary holdover from humans’ very early days. Tadpoles have been suggested as providers of potential clues, as they exhibit a hiccup-like movement when breathing water.

Number 9. Creating art. Sure, it’s one of the defining characteristics of humans and the societies they form, but why the drive to create and experience it exists remains unknown. Just as there are myriad theories about what defines art itself, there are a plethora of thoughts on what fueled its early existence and changes over time. 
Number 8. Dominant hands. It would make much more sense if humans had two hands that were fully dexterous, but somehow we ended up with one, typically the right. A popular, albeit problematic, theory is that the right hand is typically run by the left side of the brain that tackles language and fine motor skills, giving the right hand dominance. This is not always the case however. 

Number 7. Bioluminescence. Fireflies and jellyfish aren’t the only creatures that get to glow. Humans emit an aura of light as well, although it can’t be seen with the naked eye. While it serves other species well, often in their ability to attract a mate, it doesn’t seem to do anything of note for people. 

Number 6. Male nipples. Clearly, males don’t nurse young, so it’s unclear why they have them - blood vessels, nerve endings and all. It’s believed that it may have something to do with the fact that all babies start off as being female. It takes up to 2 months for testosterone to get to work in those sporting a y chromosome. 
Number 5. Blushing. In the presence of social attention, humans have a weird biological response that causes their facial veins to open up and deliver more blood to the surface. That’s what turns faces red. Why the body thinks that’s an appropriate response to feeling embarrassed or frazzled is something only it knows. 
Number 4. Laughter. It’s a communication form that transcends all language barriers, but why the body responds to certain stimuli in this way and as intensely as it does is something that has long escaped the grasp people who study such things. It’s been suggested that it may function as a social bonding mechanism, for better or for worse. 
Number 3. Kissing. It’s used to both test compatibility and maintain relationships, but it’s unclear if it accomplishes those things through actual instinct or learned behavior. There’s also little indication as to when the practice began. 
Number 2. Pubic hair. This is another case of evolution somehow not tossing out body features that are no longer needed for any sort of survival. One of the more creative guesses as to why it exists in the first place is as a guard against friction. Back in the days before undergarments and pants, there was quite possibly a need to prevent skin from rubbing on skin while walking about. 
Number 1. Consciousness. It’s a phenomenon that lets us know that it exists, yet doesn’t allow for any satisfying explanation of how or why it does. Many have tried to figure it out on both philosophical and physical levels, but definitive answers have proven consistently elusive. 
What do you think is the greatest mystery of the human body?