Yawns are more contagious among people with closer relationships.
163
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
Your thumb is about the same size as your nose.
124
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
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
The average person's skin weighs twice as much as their brain.
131