Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Enamel is hardest substance in the human body.
61
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
The average person's skin weighs twice as much as their brain.
131
Yawns are more contagious among people with closer relationships.
163
The average sperm cell swims at 8 inches per hour.
76