The largest cell in the human body is the female egg and the smallest is the male sperm.
682
It takes about 20 seconds for a red blood cell to circle the whole body.
102
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Chewing gum boosts your brain power.
285