The human body really is amazing. Check out these fantastic facts:

1. Approximately 80-90% of what we perceive as "taste" actually is due to our sense of smell.

2. Your heart beats about 35 million times in a year. During an average lifetime, the human heart will beat more than 2.5 billion times.

3. Your body has about 5.6 liters (6 quarts) of blood. This 5.6 liters of blood circulates through the body three times every minute. In one day, the blood travels a total of 19,000 km (12,000 miles)- that's four times the distance across the U.S. from coast to coast.

4. The heart pumps about 1 million barrels of blood during an average lifetime - that's enough to fill more than 3 super tankers.

5. If all arteries, veins, and capillaries of the human circulatory system were laid end to end, the total length would be 60,000 miles, or 100,000 km. That's nearly two and a half times around the Earth!

6. Even though its thickness averages just 2mm, your skin gets an eighth of all your blood supply.

7. The skull looks as though it is a single bone. In fact, it is made up of 22 separate bones, cemented together along rigid joints called sutures.

8. If a human adult's digestive tract were stretched out, it would be 6 to 9 m (20 to 30 ft) long.

9. Red blood cells may live for about four months circulating throughout the body, feeding the 60 trillion other body cells. Red blood cells make approximately 250,000 round trips of the body before returning to the bone marrow, where they were born, to die.

10. Human hair grows about 1/4 inch (about 6 millimeters) every month and keeps on growing for up to 6 years. The hair then falls out and another grows in its place.

11. The average healthy mouth produces about 600 milliliters of saliva each day. That's enough to fill a 12-ounce soda bottle.

12. The fastest nerve cells are carrying messages along their axons at an amazing 130 yards per second (268 mph).