For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The human brain doesn't stop developing until about 25 years old.
102
You can hear the blood flowing through your ears if you find a quiet place and cover them tightly.
19
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
The human brain uses approximately as much energy as a 10 watt light bulb.
120
The levels of two stress hormones, cortisol and epinephrine which suppress the body's immune system, will actually drop after a dose of laughter.
112
The brain receives 20% of the body’s oxygen and 25% of total body glucose utilization, despite it accounting for only 2% of a person’s weight (about 1.4 kilograms).
8
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22