Resumo de Book Of Facts - Reader's Digest

MARVELS OF THE HUMAN BODY
FACTS AND FIGURES ABOUT THE ASTONISHING BODY
·
· Doubling a child?s height on his second birthday gives a close estimate of his final adult height. A boy of two is 49.5% of its adult height; a girl of two is 52.8% of her adult height.
· Each finger and toenail takes about six months to grow from its base to the tip.
· During pregnancy a woman?s blood volume can increase by up to 50% to a total of 6.75 litres as a reserve against possible loss blood during delivery.
· The brain contains for about 3% of body weight. But it uses 20% of all the oxygen we breathe 20% of the calories in the food we eat and about 15% of the body?s blood supply.
· The adult human body contains approximately 650 muscles, over 100 joints, 100,000km of blood vessels and 13000million nerve cells. An adult have 206 bones- nearly half of them in the hands and feet. A baby has 300 bones at birth, but 94 fuses together during childhood.
· Human bone is as strong as granite in supporting weight. A block the size of a matchbox can support 9 tonnes- four times as much as concrete.
· A man?s testicles manufacture 10 million new sperm cells a day- enough in six months to populate the entire world.
· The body of the average adult contains 45 litres of water- about 65% of his weight.
· The stomach?s digestive acids are strong enough to dissolve zinc. But the cells in the stomach lining are renewed so quickly- 500,000 cells are replaced every minute and the entire lining every three days- that the acids do not have time to dissolve the lining.
· The body?s largest organ is the skin. In an adult man it covers about 1.9m2; a woman has about 1.6m2. The skin is constantly flaking away and being completely replaced by new tissue about once every 50 days. On average, each person sheds about 18kg of skin during his lifetime.
· You grow by about 8mm every night when you are asleep, but shrink to your normal height the following day. During the day, the cartilage discs in the spine are squeezed like sponges by gravity while you stand or sit. But at night, when you lie down to sleep, the pressure is relieved and the discs swell again. For the same reason, astronauts can be temporarily 50mm taller after a long spaceflight.
· The focusing muscles of the eye move about 100,000 times a day. To give the leg muscles the same exercise would involve walking 80km a day.

Resumos Relacionados