20 Strange Facts Of Human Body 1. Every hour one billion cells in the body must be replaced. 2. The eye of a human can distinguish 500 shades of the gray. 3. Human thighbones are stronger than concrete. 4. The human heart creates enough pressure to squirt blood 30 feet (9 m). 5. Our eyes are always the same size from birth, but our nose and ears never stop growing. 6. The average cough comes out of your mouth at 60 miles (96.5 km) per hour. 7. Beards are the fastest growing hairs on the human body. If the average man never trimmed his beard, it would grow to nearly 30 feet long in his lifetime. 8. Babies’ eyes do not produce tears until the baby is approximately six to eight weeks old. 9. Every person has a unique tongue print. 10. A sneeze can exceed the speed of 100 mph. 11. Dead cells in the body ultimately go to the kidneys for excretion. 12. The smile is the most frequently used facial expression. A smile can use anywhere from a pair of 5 to 53 facial muscles. 13. One out of 20 people have an extra rib. 14. People with darker skin will not wrinkle as fast as people with lighter skin. 15. Human blood travels 60,000 miles (96,540 km) per day on its journey through the body. 16. 85% of the population can curl their tongue into a tube. 17. It takes food seven seconds to go from the mouth to the stomach via the esophagus. 18. Women hearts beat faster than men. 19. In one day your heart beats 100,000 times. 20. Hair is made from the same substance as fingernails.