The average sperm cell swims at 8 inches per hour.
76
Yawns are more contagious among people with closer relationships.
163
Your body is creating and killing about 2.4 million red blood cells per second.
17
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
The human brain doesn't stop developing until about 25 years old.
102
When you take a step, you are using up to 200 muscles.
885
Your heart will pump about 212 million liters in its lifetime.
26