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
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
The average sperm cell swims at 8 inches per hour.
76
Yawns are more contagious among people with closer relationships.
163
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55