THE BRAIN Crossing your arms can reduce pain by confusing your brain. People generally read from paper 25% faster than from a computer monitor. Once we reach the age of 35, we will start losing approximately 7,000 brain cells each day—cells that will never be replaced Your brain is about 2% of your total body weight but uses 20% of your all your body's oxygen and calories. The average human dream lasts only two to three seconds and the average person has at least seven dreams a night. People with higher IQs have more dreams. Shoes are now available with a built-in GPS to help locate people with Alzheimer's or other dementia who have wandered away. STAYING HEALTHY Some dogs can detect early-stage lung cancer in people based solely on their sense of smell. Over 90% of diseases are caused or complicated by stress. Every three minutes a woman is diagnosed with breast cancer somewhere in the world. The electromagnetic fields produced by mobile phones are classified by the International Agency for Research on Cancer as possibly carcinogenic to humans. In some Asian and African countries, 80% of the population depends on traditional medicine for primary health care. The hepatitis B virus is 50 to 100 times more infectious than HIV. Road traffic injuries are the leading cause of death among young people, aged 15–29 years. Tobacco kills up to half of its users. A needle-free, “nanopatch” vaccine delivery system is being developed that could eliminate the need for shots. HAIR & SKIN The main purpose of eyebrows is to keep sweat out of the eyes. Female hair grows more slowly than male hair. Humans have about the same number of hair follicles as a chimpanzee has. Hair will fall out faster on a person who is on a crash diet. Eyebrow hair lasts between 3-5 months before it sheds and an eyelash has a lifespan of about 150 days. Every half square inch of the human skin has about 100 sweat glands, 10 hairs, 15 sebaceous glands, and just under a meter of blood vessels. The average adult skin has an area of about 2 square meters and weighs about 2.5 to 4 kilograms. The entire skin system has about 17 kilometers of blood vessels and 72 kilometers of nerves. The skin constantly renews itself every 27 or 28 days for a total of 1,000 new “suits” of skin in an average lifetime. THE HEART & BLOOD Blood is about 78% water. The human heart weighs less than 454 grams. The longer the ring finger is in males, the less chance they have of having a heart attack. The risk of cardiovascular disease is twice as high in women who snore regularly compared to women who do not snore. Warfarin, used to clot blood and to prevent blood clots from moving, is the most widely used anticoagulant in North America, but it was originally developed as a pesticide against rodents and it is still available for that purpose. People who ride on roller coasters have a higher chance of getting a blood clot in the brain. HISTORY New anti-malarial drugs were developed from a plant that been used medicinally in China for almost 2000 years. In ancient Egypt, medical institutions were called "Houses of Life." Tibetan anatomists counted a total of 360 bones in an adult human body, while Western medical books say 206, because they considered cartilage, fingernails, and toenails as bones. Mustargen (nitrogen mustard) is a poisonous gas and blistering agent once used in chemical warfare that is also used as a powerful anticancer drug. Botox was discovered in the fat of spoiled pork and was called botulism by the doctor who figured out a medicinal use for it. In the 1960's it was used to correct cross-eyed syndrome. The oldest known disease in the world is leprosy. In the early 19th century some people believed that riding a carousel was good for blood circulation. EATING & OVEREATING It takes your food about seven seconds to get from your mouth to your stomach. The human liver performs over 500 functions. Overeating reduces your ability to hear. The CDC reports that more people are overweight than underweight worldwide. Annual flu shots may be less effective for obese people. You will die from a lack of sleep before you will die from a lack of food. CHILDREN Over one third of all child deaths worldwide are linked to malnutrition. Six-year-olds laugh an average of 300 times a day. Adults only laugh 15 to 100 times a day. Babies are born color-blind. Babies' eyes do not produce tears until they are approximately six to eight weeks old. Pneumonia is the leading cause of death in children worldwide– more than AIDS, malaria, and tuberculosis combined. Your brain changes shape during puberty. REPRODUCTION 10% of all human beings ever born are alive at this very moment. The earliest documented occurrence of a fetus yawning is at eleven weeks after conception. During a normal pregnancy, the average woman's uterus expands up to five hundred times its normal size. 99% of all maternal deaths (death from childbirth) occur in developing countries. Women who smoke take longer to conceive, suffer from infertility at higher rates, and have higher rates of miscarriage. Babies hiccup while still in the womb because the respiratory center of a developing child’s brain works just like that of an adult, even though they are not yet breathing air. SENSES Our eyes can distinguish up to one million color surfaces and take in more information than the largest telescope known to man. Half of all cases of deafness and hearing impairment worldwide could be avoided by prevention, early diagnoses, and proper treatment. A scent membrane in a human’s nose is about the size of a postage stamp. A dog’s is about the size of a handkerchief. About 80% of all visual impairments worldwide could be avoided or cured. The eyeball of a human weighs approximately 28 grams. Under the right conditions, the human eye can see candlelight from 22 kilometers away. The eye of a human can distinguish 500 shades of the gray. MUSCLES & BONES The only bone not connected to another is the hyoid, found under the chin and at the base of the tongue. The only bone fully grown at birth is located in the ear. The human face is made up of 14 bones. The strongest bone in your body is hollow (the femur). You use up to 200 muscles to take a step. The average person walks the equivalent of twice around the world in a lifetime. TEETH Your teeth started to grow as early as six months before you were born. People that suffer from gum disease are twice as likely to have a stroke or heart attack. Smokers are twice as likely to lose teeth as nonsmokers. A pregnant woman's dental health can affect her unborn child. Some brands of toothpaste contain an ingredient found in antifreeze (glycerin or glycerol). Source