Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
132
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Yawns are more contagious among people with closer relationships.
163
Tigers can see 6 times better at night than humans.
305
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Having sex can make a woman look younger and more attractive due to the release of estrogen and collagen.
346