This segment was originally broadcast on March 13, 2008. It was updated on June 12, 2008.
Human beings spend on average one third of our lives asleep. We know we need to sleep, but most of us have never really given a whole lot of thought to why.
Why do we spend seven or eight hours a https://www.healthcare.gov/center/ night immobile and unconscious? What really happens inside our brains and bodies while we're sleeping?
As correspondent Lesley Stahl first reported this spring, it's one of the biggest unanswered questions in all of science, which is why researchers all over the country are doing studies, and coming up with some new, intriguing discoveries.
"We don't sleep just to rest our tired bodies?" Stahl asks Matthew Walker, the director of the Sleep and Neuroimaging Lab at the University of California, Berkeley.
"Well, that's been one of the long-standing theories. But I think what we're starting to understand is that sleep serves a whole constellation of functions, plural," Walker explains.
One thing that's clear, says Walker, is that sleep is critical. In a series of studies done back in the 1980s, rats were kept awake indefinitely. After just five days, they started dying.
Walker says they started dying from sleep deprivation. "In fact, sleep is as essential as food because they will die just about as quick from food deprivation as sleep deprivation. So, it's that necessary," he says.
And it's not just rats: every animal studied so far needs sleep, from the elephant right down to the fruit fly. But that's as far as the similarities go. Some animals sleep 20 hours a day, others only two or three. And still others sleep with half their brains at a time, all making it hard to figure out what exactly it is about sleep that makes it so essential, and that, in terms of evolution, makes it worth the risks.
"You wonder why we developed this if survival is the whole point. Because you're completely vulnerable when you're lying there," Stahl points out.
"Whatever the function of sleep, or the functions of sleep are, they seem to be so important that evolution is willing to put us in that place of potential danger by losing consciousness. It would be the biggest evolutionary mistake if sleep does not healthcare advertising and promotion serve some critical function," Walker says.
One of the most exciting new discoveries in the field of sleep research involves learning and memory.
Five college students were subjects in one of Walker's studies, and they had been awake for more than 24 hours. He has found that students like these do 40 percent worse memorizing lists of words after a night without sleep. But he has discovered something far more revolutionary about what happens when we do sleep.
"Sleep, we've been finding, actually can enhance your memories, so that you'll come back the next day even better than where you were the day before," Walker tells Stahl.
To prove it, Walker put Stahl through a test he's given to more than 400 study subjects. Stahl had to type a series of numbers - 4, 1, 3, 2, 4 - over and over again with her left hand, making a new physical memory.
Your teeth make a huge first impression on people. This is just one reason you should keep your teeth in good shape. This article will provide you with some tips on dental care which will get your teeth in the best condition ever.
If you're seeing blood when you are trying to brush your teeth, you probably should make an appointment to see your dentist. Don't ignore the most common sign of gum disease -- bleeding, painful gums. Gum disease can cause bones loss, tooth loss, infections, and diabetes.
Consider trying dental cleaners on teeth in order to boost your dental health. These are usually disposable brushes used to clean between brushings, and you can also use them to clea
Judging from what archaeologists have learned from examining the bones and teeth of long-dead humans, people have been bothered by dental problems for thousands of years. Simply put, many of these ancient folk had holes in their teeth and probably suffered from toothaches and also abscesses, whose pain can be excruciating. At least in some places, they did what they could. Evidence of the use of dental drills has been found in Neolithic graves in Pakistan. (The Neolithic Age lasted from 12,000 to 5,000 years ago.) But whether this procedure brought relief to anyone is open to conjecture, of course.
The earliest writing regarding toothaches took place about 5,000 years ago in Mesopotam
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From certain medications to stress or genetics, many different factors can cause hair thinning. The good news is that there are many resources available to help you reduce hair thinning or conceal the signs of hair thinning. Consider the advice in this article to help you successfully deal with thinning hair.
Utilizing a diet that is rich in protein will help you prevent thinning hair. This is because hair is made from protein. To get protein, you should consume fish, red meat, poultry and eggs. Beans and lentils are an alternative source of protein if you are not a fan of red meat. Eating more protein can actually reduce the amount of hair you lose.
Thinning hair can be caused by certain hair styles. If you are tying your hair back with a rubber band, or pulling it to tight to put it into a ponytail, this is not a good idea for long time periods. Although hair barrettes and other products have certainly gotten better over time, many still do damage to your hair. Wearing tight ponytails causes damage to your hair shaft, gradually damaging hair follicles.
Avoid products used in hair styling to keep the loss of hair from becoming a problem. You may not be able to avoid these entirely, but you should keep their use to a minimum. These products often have chemicals that lead to your hair falling out.
Liquid saw palmetto is great for men to use that have started to notice blading. This natural extract reduces how much DHT you produce, a hormone that causes blading. The juice can be squeezed from the fruit and put directly into your hair.
Whether you have lost just a little hair or all of it, the advice you just read should help you deal with your the loss of hair in the most effective way possible. By learning the causes and symptoms of losing hair, you can treat hair thinning effectively.