It takes about 20 seconds for a red blood cell to circle the whole body.
102
The human brain doesn't stop developing until about 25 years old.
102
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 average person's skin weighs twice as much as their brain.
131
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
Your thumb is about the same size as your nose.
124
Yawns are more contagious among people with closer relationships.
163
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18