It takes about 20 seconds for a red blood cell to circle the whole body.
102
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Your thumb is about the same size as your nose.
124
Enamel is hardest substance in the human body.
61
The human brain doesn't stop developing until about 25 years old.
102
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
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
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118