If you were to roll a lung from a human body and out flat it would be the size of a tennis court.
36
By weight, Bone is five times stronger than steel.
417
The focusing muscles of the eyes move around 100,000 times a day. To give your leg muscles the same workout, you would need to walk 80km (50 miles) every day.
21
Falling in love raises levels of nerve growth in a person's brain for about a year and can improve their memory.
39
About half of all Americans are on a diet on any given day.
29
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
About 400 different kinds of microbes live on and in the human body.
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