100 amazing medical facts of your body...part 3

41. 10% of human dry weight comes from bacteria.

42. There is more bacteria in your mouth than the human population of the
United States and Canada combined .

43. Every square inch of the human body has an average of 32 million bacteria on it.

44. A fetus acquires fingerprints at the age of three months

45. You sit on the biggest muscle in your body, the gluteus maximus a.k.a. the butt. Each of the two cheeky muscles tips the scales at about two pounds (not including the overlying fat layer).

46. The tiniest muscle, the stapedius of the middle ear , is just one-fifth of an inch long.

47. The average human head weighs about 10 pounds.

48. The average human brain weighs three pounds.

49. The DNA helix measures 80 billionths of an inch wide.

50. Your eyeballs are three and a half percent salt.

51. Head lice actually prefer to live on clean heads, not on dirty ones.

52. If Barbie were life-size, her measurements would be 39-23-33. She would stand seven feet, two inches tall and have a neck twice the length of a normal human's neck.

53. It takes about 20 seconds for a red blood cell to circle the whole body.

54. An average human drinks about 16,000 gallons of water in a lifetime.

55. Beards are the fastest growing hairs on the human body. If the average man never trimmed his beard, it would grow to nearly 30 feet long in his lifetime.

56. Humans shed about 600,000 particles of skin every hour - about 1.5 pounds a year. By 70 years of age, an average person will have lost 105 pounds of skin.

57. It only takes 7lbs of pressure to rip your ear off.

58. When you sneeze, all your bodily functions stop - even your heart.

59. Human teeth are almost as hard as rocks.

60. You burn more calories sleeping than you do watching T.V.