Your thumb is about the same size as your nose.
124
Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
132
Enamel is hardest substance in the human body.
61
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Only humans shed emotional tears.
331
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Some monks can increase their body temperature so much they can dry soaking sheets in a freezing room!
32
Having sex can make a woman look younger and more attractive due to the release of estrogen and collagen.
346