Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your heart will pump about 212 million liters in its lifetime.
26
The average human body contains enough fat to make seven bars of soap.
45
Ingrown toenails are hereditary.
15
Pain travels through the body at 350 feet per second!
23
According to a 1950s survey, 75% of men ejaculate within two minutes of penetration.
109
Crushed cockroaches can be applied to a stinging wound to help relieve the pain.
31
All humans have the ability to see ultraviolet light, but it is passively filtered out by the eye's lens. People who undergo surgery to remove the lens can detect ultraviolet light.
22