Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain doesn't stop developing until about 25 years old.
102
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13