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
Yawns are more contagious among people with closer relationships.
163
The average person's skin weighs twice as much as their brain.
131
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
The human brain doesn't stop developing until about 25 years old.
102
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
The average sperm cell swims at 8 inches per hour.
76