1. The total surface area of your lungs is approximately 70 square meters – roughly the same size as a singles badminton court.
2. You shed and regrow your outer skin cells about every 27 days – almost 1,000 new skins in a lifetime.
3. Each square inch of your skin consists of over 6 meters of blood vessels.
4. 11% of the world is left-handed.
5. You use 17 muscles to smile and 43 to frown.
6. On average women say 7,000 words per day. Men manage just over 2,000.
7. The largest cell in the human body is the female reproductive cell, the ovum. The smallest is the male sperm.
8. After spending hours working at a computer display, look at a blank piece of white paper – it will probably appear pink.
9. Blondes have more hair than dark-haired people.
10. One in every 2,000 babies is born with a tooth.
11. The average human body has enough fat to produce 7 bars of soap.
12. Every person has a unique tongue print.
13. Babies are born with 300 bones, but by adulthood you have only 206 in your body.
14. If it were removed from your body, your small intestine would stretch to a length of 6.7 meters.
15. The most common blood type in the world is Type O. The rarest, Type A-H, has been found in less than a dozen people since the type was discovered.
16. You lose an average of 40 to 100 strands of hair a day.
17. Your body has over 600 muscles, 40% of your body’s weight.
18. Your largest organ is your skin, with a surface area of about 25 square feet.
19. The only bone in your body not connected to another is your hyoid, a V-shaped bone located at the base of your tongue between your mandible and voice box. Its function is to support your tongue and its muscles.
20. Laughing lowers levels of stress hormones and strengthens your immune system.
21. A recent study indicates when men crave food, they tend to crave fat and salt. When women crave food, they tend to desire chocolate.
22. An individual blood cell takes about 60 seconds to make a complete circuit of your body.
23. By age sixty, most people have lost half of their taste buds.
24. Six-year-olds laugh an average of 300 times a day. Adults only laugh 15 to 100 times a day.
25. According to German researchers, the risk of heart attack is higher on Monday than any other day of the week.
26. By the time you turn 70, your heart will have beat some two-and-a-half billion times.
27. A fetus acquires fingerprints at the age of three months.
28. The longest muscle in your body is the sartorius. This narrow muscle of the thigh passes obliquely across the front of your thigh and helps rotate your leg to the position assumed in sitting cross-legged.
29. A human’s scent membrane in the nose is about the size of a postage stamp. Your body produce about 70 kg of ATP (a molecule that stores energy, permitting you to do nearly everything your body does) each day.
30. You produce 1.7 liters of saliva each day.
31. The attachment of human muscles to skin is what causes dimples.
32. Women blink twice as much as men.
33. Your ears secrete more earwax when you’re afraid than when you aren’t.
34. Even though your brain processes pain signals, the brain itself does not actually feel pain.
35. Compared to its size, your tongue is the strongest muscle in your body
36. It’s impossible to tickle yourself.
37. There are 250,000 sweat glands in each of your feet – they can produce almost half a liter of sweat a day.
38. Even though your brain only makes up 2% of your total body weight, it requires 20%of the oxygen and calories your body needs.
39. Humans are the only creatures that shed emotional tears.
40. Most babies are born with blue eyes, until melanin and exposure to ultraviolet light bring out their true color.
41. Your brain is most active when you sleep.
42. The muscles of your eyes move more than 100,000 times a day
43. Your body consists of over 600 muscles.
44. An average human head weighs about 8 pounds
45. The length of the finger indicates how fast the nail grows. The nail of the middle finger grows faster than others.
46. The total weight of skin in an average human adult is 61 pounds (27.7kg).
47. Your body produce about 70 kg of ATP (a molecule that stores energy, permitting you to do nearly everything your body does) each day.
48. The average human body contains enough potassium to fire a toy cannon.
49. It takes about 175,000 sperm cells to weigh as much as one single egg cell.
50. If you were locked in a completely sealed room, you would die of carbon dioxide poisoning first before you died of oxygen deprivation.