Health: Weird Facts About the Human Body

The human body is an incredibly complex and intricate system, one that still baffles doctors and researchers on a regular basis despite thousands of years of medical knowledge. As a result, it shouldn’t be any surprise that even body parts and functions we deal with every day have bizarre or unexpected facts and explanations behind them

1. Nerve impulses to and from the brain travel as fast as 170 miles per hour. Ever wonder how you can react so fast to things around you or why that stubbed toe hurts right away? It’s due to the superspeedy movement of nerve impulses from your brain to the rest of your body and vice versa, bringing reactions at the speed of a high powered luxury sports car.
2. The human brain cell can hold 5 times as much information as the Encyclopedia
   Britannica. Or any other encyclopedia for that matter. Scientists have yet to settle on a definitive amount, but the storage capacity of the brain in electronic terms is thought to be between 3 or even 1,000 terabytes. The National Archives of Britain, containing over 900 years of history, only takes up 70 terabytes, making your brain’s memory power pretty darn impressive. 
3. The brain is much more active at night than during the day. Logically, you would think that all the moving around, complicated calculations and tasks and general interaction we do on a daily basis during our working hours would take a lot more brain power than, say, lying in bed. Turns out, the opposite is true. When you turn off your brain turns on. Scientists don’t yet know why this is but you can thank the hard work of your brain while you sleep for all those pleasant dreams. 
4. Neurons continue to grow throughout human life.  For years scientists and doctors thought that brain and neural tissue couldn’t grow or regenerate. While it doesn’t act in the same manner as tissues in many other parts of the body, neurons can and do grow throughout your life, adding a whole new dimension to the study of the brain and the illnesses that affect it. 
5. The brain itself cannot feel pain. While the brain might be the pain center when you cut your  finger or burn yourself, the brain itself does not have pain receptors and cannot feel pain. That doesn’t mean your head can’t hurt. The brain is surrounded by loads of tissues, nerves and blood vessels that are plenty receptive to pain and can give you a pounding headache.
6. 80% of the brain is water. Your brain isn’t the firm, gray mass you’ve seen on TV. Living brain tissue is a squishy, pink and jellylike organ thanks to the loads of blood and high water content of the tissue. So the next time you’re feeling dehydrated get a drink to keep your brain hydrated.
7. Facial hair grows faster than any other hair on the body.  If you’ve ever had a covering of stubble on your face as you’re clocking out at 5 o’clock you’re probably pretty familiar with this. In fact, if the average man never shaved his beard it would grow to over 30 feet during his lifetime, longer than a killer whale. 
8. Women’s hair is about half the diameter of men’s hair. While it might sound strange,
   it shouldn’t come as too much of a surprise that men’s hair should be coarser than that of women. Hair diameter also varies on average between races, making hair plugs on some men look especially obvious. 
9. The fastest growing nail is on the middle finger. And the nail on the middle finger of
   your dominant hand will grow the fastest of all. Why is not entirely known, but nail growth is related to the length of the finger, with the longest fingers growing nails the fastest and shortest the slowest.
10. Fingernails grow nearly 4 times faster than toenails. If you notice that you’re trimming your fingernails much more frequently than your toenails you’re not just imagining it. The nails that get the most exposure and are used most frequently grow the fastest. On average, nails on both the toes and fingers grow about onetenth of an inch each month.
11. Human hair is virtually indestructible. Aside from it’s flammability, human hair decays at such a slow rate that it is practically nondisintegrative. If you’ve ever wondered how your how clogs up your pipes so quick consider this: hair cannot be destroyed by cold, change of climate, water, or other natural forces and it is resistant to many kinds of acids and corrosive chemicals.
12. The largest internal organ is the small intestine. Despite being called the smaller of the two intestines, your small intestine is actually four times as long as the average adult is tall. If it weren’t looped back and forth upon itself it wouldn’t fit inside the abdominal cavity.
13. The human heart creates enough pressure to squirt blood 30 feet. No wonder you can  feel your heartbeat so easily. Pumping blood through your body quickly and efficiently takes quite a  bit of pressure resulting in the strong contractions of the heart and the thick walls of the  entricles which push blood to the body.
14. The acid in your stomach is strong enough to dissolve razorblades. While you certainly shouldn’t test the fortitude of your stomach by eating a razorblade or any other metal object for that matter, the acids that digest the food you eat aren’t to be taken lightly. Hydrochloric acid,  the type found in your stomach, is not only good at dissolving the pizza you had for dinner but can also eat through many types of metal.
15. The human body is estimated to have 60,000 miles of blood vessels. To put that in  perspective, the distance around the earth is about 25,000 miles, making the distance your blood vessels could travel if laid end to end more than two times around the earth. 
16. You get a new stomach lining every three to four days.  The mucus like cells lining the walls of the stomach would soon dissolve due to the strong digestive acids in your stomach if they weren’t constantly replaced. Those with ulcers know how painful it can be when stomach acid takes its toll on the lining of your stomach. 
17. The surface area of a human lung is equal to a tennis court. In order to more efficiently oxygenate the blood, the lungs are filled with thousands of branching bronchi and tiny, grapelike alveoli. These are filled with microscopic capillaries which oxygen and carbon  dioxide. The large amount of surface area makes it easier for this exchange to take place, and makes sure you stay properly oxygenated at all times
18. Women’s hearts beat faster than men’s.The main reason for this is simply that on
    average women tend to be smaller than men and have less mass to pump blood to. But
    women’s and men’s hearts can actually act quite differently, especially when
    experiencing trauma like a heart attack, and many treatments that work for men must be
    adjusted or changed entirely to work for women.
19. Scientists have counted over 500 different liver functions. You may not think much
    about your liver except after a long night of drinking, but the liver is one of the body’s
    hardest working, largest and busiest organs. Some of the functions your liver performs
    are: production of bile, decomposition of red blood cells, plasma protein synthesis, and
    detoxification.
20. Your left lung is smaller than your right lung to make room for your heart. For most  people, if they were asked to draw a picture of what the lungs look like they would draw both looking roughly the same size. While the lungs are fairly similar in size, the human heart, though located fairly centrally, is tilted slightly to the left making it take up more room on that side of the body and crowding out that poor left lung.
21. The adrenal glands change size throughout life. The adrenal glands, lying right above the kidneys, are responsible for releasing stress hormones like cortisol and adrenaline. In the seventh month of a fetus’ development, the glands are roughly the same size as the kidneys. At birth, the glands have shrunk slightly and will continue to do so throughout life. In fact, by the time a person reaches old age, the glands are so small they can hardly be seen. 
22.  Sneezes regularly exceed 100 mph. There’s a good reason why you can’t keep your eyes open when you sneeze–that sneeze is rocketing out of your body at close to 100
    mph. This is, of course, a good reason to cover your mouth when you sneeze.
23.  Women blink twice as many times as men do. That’s a lot of blinking every day. The average person, man or woman, blinks about 13 times a minute.
24.  A full bladder is roughly the size of a soft ball. No wonder you have to run to bathroom when you feel the call of the wild. The average bladder holds about 400-800 cc of fluid
    but most people will feel the urge to go long before that at 250 to 300 cc
25. Approximately 75% of human waste is made of water. While we might typically think that urine is the liquid part of human waste products, the truth is that what we consider solid waste is actually mostly water as well. You should be thankful that most waste is fairly waterfilled,
    as drier harder stools are what cause constipation and are much harder and sometimes painful to pass 
26.  During your lifetime, you will produce enough saliva to fill two swimming pools. Saliva plays an important part in beginning the digestive process and keeping the mouth lubricated, and your mouth produces quite a bit of it on a daily basis.
27.  Earwax production is necessary for good ear health. While many people find earwax to be disgusting, it’s actually a very important part of your ear’s defense system. It protects the delicate inner ear from bacteria, fungus, dirt and even insects. It also cleans and lubricates the ear canal.
28.  On any given day, sexual intercourse takes place 120 million times on earth. Humans are a quickly proliferating species, and with about 4% of the world’s population having sex on any given day, it’s no wonder that birth rates continue to increase in many places all over the world.
29. The largest cell in the human body is the female egg and the smallest is the male sperm. While you can’t see skin cells or muscle cells, the ovum is typically large enough to be seen with the naked eye with a diameter of about a millimeter. The sperm cell, on the other hand, is tiny, consisting of little more than nucleus.
30.  A fetus acquires fingerprints at the age of three months. When only a small fraction of the way through its development, a fetus will have already developed one of the most unique human traits: fingerprints. At only 6-13 weeks of development, the whorls of what will be fingerprints have already developed. Oddly enough, those fingerprints will not change throughout the person’s life and will be one of the last things to disappear after death.
31. Every human spent about half an hour as a single cell. All life has to begin somewhere, and even the largest humans spent a short part of their lives as a single celled organism when sperm and egg cells first combine. Shortly afterward, the cells begin rapidly dividing and begin forming the components of a tiny embryo.
32. Most men have erections every hour to hour and a half during sleep. Most people’s bodies and minds are much more active when they’re sleeping than they think. The combination of blood circulation and testosterone production can cause erections during sleep and they’re often a normal and necessary part of REM sleep. 
33.  After eating too much, your hearing is less sharp. If you’re heading to a concert or a
    musical after a big meal you may be doing yourself a disservice. Try eating a smaller meal if you need to keep your hearing pitch perfect 
34. Your nose can remember 50,000 different scents. While a bloodhound’s nose may be a million times more sensitive than a human’s, that doesn’t mean that the human sense of smell is useless. Humans can identify a wide variety of scents and many are strongly tied to memories.
35. Everyone has a unique smell, except for identical twins. Newborns are able to
    recognize the smell of their mothers and many of us can pinpoint the smell of our significant others and those we are close to. Part of that smell is determined by genetics, but it’s also largely do to environment, diet and personal hygiene products that create a unique chemistry for each person.
36. By 60 years of age, 60-percent of men and 40percent of women will snore. If you’ve ever been kept awake by a snoring loved one you know the sound can be deafening. Normal snores average around 60 decibels, the noise level of normal speech, intense snores can reach more than 80 decibels, the approximate level caused by a jackhammer breaking up concrete.
37.  A baby’s head is one-quarter of it’s total length, but by age 25 will only be one-eighth of its total length. As it turns out, our adorably oversized baby heads won’t change size as drastically as the rest of our body. The legs and torso will lengthen, but the head won’t get much longer.
38. Humans can make do longer without food than sleep. While you might feel better prepared to stay up all night partying than to give up eating, that feeling will be relatively short lived. Provided there is water, the average human could survive a month to two months without food depending on their body fat and other factors. Sleep deprived people, however, start experiencing radical personality and psychological changes after
    only a few sleepless days. The longest recorded time anyone has ever gone without sleep is 11 days, at the end of which the experimenter was awake, but stumbled over words, hallucinated and frequently forgot what he was doing. 
39.  It takes 17 muscles to smile and 43 to frown. Unless you’re trying to give your face a bit of a workout, smiling is a much easier option for most of us. Anyone who’s ever scowled, squinted or frowned for a long period of time knows how it tires out the face which doesn’t do a thing to improve your mood.
40.  You use 200 muscles to take one step. Depending on how you divide up muscle groups,just to take a single step you use somewhere in the neighborhood of 200 muscles. That’s a lot of work for the muscles considering most of us take about 10,000 steps a day.
41.  The tooth is the only part of the human body that can’t repair itself. If you’ve ever chipped a tooth you know just how sadly true this one is. The outer layer of the tooth is enamel which is not a living tissue. Since it’s not alive, it can’t repair itself, leaving your dentist to do the work instead.
42. Three hundred million cells die in the human body every minute. While that sounds like a lot, it’s really just a small fraction of the cells that are in the human body. Estimates have placed the total number of cells in the body at 10-50 trillion so you can afford to
    lose a few hundred million without a hitch.
43.  Women burn fat more slowly than men, by a rate of about 50 calories a day. Most men have a much easier time burning fat than women. Women, because of their reproductive role, generally require a higher basic body fat proportion than men, and as a result their bodies don’t get rid of excess fat at the same rate as men.