Yawns are more contagious among people with closer relationships.
163
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
The human brain doesn't stop developing until about 25 years old.
102
Your body is creating and killing about 2.4 million red blood cells per second.
17
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13