Yawns are more contagious among people with closer relationships.
163
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
The average person's skin weighs twice as much as their brain.
131
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
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
When you take a step, you are using up to 200 muscles.
886