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
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
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Your heart will pump about 212 million liters in its lifetime.
26
Your body is creating and killing about 2.4 million red blood cells per second.
17
One human hair can support 3 ounces.
191
The average person's skin weighs twice as much as their brain.
131