Your body is creating and killing about 2.4 million red blood cells per second.
17
Yawns are more contagious among people with closer relationships.
163
The average sperm cell swims at 8 inches per hour.
76
Your thumb is about the same size as your nose.
124
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
Your heart will pump about 212 million liters in its lifetime.
26
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18